"I think I have one of the best lives that any 15-year-old could have. I'm doing well on the circuit, my ranking's improving, I'm doing well in school and I have a lot of friends. There's no much more I could want." -- Andrea Jaeger

What is the price of stardom when you are 15 years old and already something of an international celebrity with a six-figure income? Well at least in the case of Andrea Jaeger, the latest prodigy of women's tennis, the toll is not very high. The biggest problem seems to be that youngsters you don't even know occassionally bug you in the corridor at school.

"Sometimes when I'm home, a lot of kids are phony. They just wanna be around me because I'm kinda like famous or something. Like when a photographer comes to school, they wanna be next to me, to be in the picture even if they don't like me or I don't even know 'em," says Jaeger, shaking her waistlength blond pigtails at the thought of such silliness.

"I mean, I don't think anybody dislikes me, but I don't know a lot of kids, and they just come around and ask if they can carry my books. Stuff like that," she said.

Golly. The cost of fame.

Jaeger is missing the opening days of her sophomore year at Adlai E. Stevenson High School in Prairie, Ill., a Chicago suburb that neighbors her hometown of Lincolnshire, because she is playing the U.S. Open tennis championships. At 15 years 2 months, she is the youngest player ever seeded in America's oldes and most prestigious tournament.

School started Wednesday, and Andrea -- a straight A student who has no trouble catching up on missed work -- may not get to any classes next week, either. Geometry, U.S. history, chemistry and business ed will have to wait, because she has an excellent chance of reaching the Open final, or even winning the $46,000 top prize.

Jaeger is seeded No. 8, but is in the quarter of the draw weakened by the withdrawal of Wimbledon champion Evonne Goolagong Cawley (bad back). Winner of 40 of the 55 matches she has played and nearly $100,000 since she turned pro on Jan. 22, Jaeger appears bound at least for the semifinals.

There she would likely meet either Martina Navratilova, who is playing so far below form that she appears to be living on borrowed time in the Open, or Hana Mandlikova, the gifted 18-year-old Czech who beat Navratilova in the semis and Jaeger in the final of the $100,000 Volvo Cup last week in Mahwah, N.J.

The tournament eventually may be remembered as the coming-out party of two newest stars of the women's game. Jaeger beat Tracy Austin, the 17-year-old reigning Open champion, marking the first time Austin has ever lost to a player younger than she. Mandlikova beat the countrywoman she idolized as a young teen in Czechoslovakia, and then defeated Jaeger to climax the best week of her two-year pro tour experience.

Jaeger took her triumph over Austin in stride, as is her wont. The day after, she shrugged it off as no big deal. "It's not like the rest of my life I'm going to put up signs on my wall that I beat Tracy Austin." she said, in a tone more insouciant than flip.

She also is a realist about the Open, where she made her debut last year and lost to Austin, 6-2, 6-2, in the second round: "I just wanna do as well as I can. I'm not going to put any pressure on myself by saying I should reach the quarters because I'm seeded eighth, or I should get to the semis or do this or do that. This is my first year as a pro here, and I'm going to do the best I can."

Asked what the victory over Austin had done for her confidence coming into the big round-up at the National Tennis Center, Jaeger said: "It really hasn't done anything because that tournament was last week and this tournament is completely different. Like the people who won the tournament the week before Wimbledon didn't win Wimbledon. I played that tournament last week because it was on the same kind of surface (rubberized asphalt hard courts) as this, but just because I beat somebody there doesn't mean I would beat them here."

Andrea Jaeger is totally, refreshingly and youthfully frank -- an energetic and remarkably well-adjusted teen who has fit easily, effortlessly into the sometimes hard-edged life of the circuit. She is almost universally liked, completely in sync with her contemporaries and adults alike.

The teen-agers think she is nifty -- "really neat," as one prepubescent autograph-seeker said outside the player's lounge yesterday. Older folks regard her as "cute" and "a really good kid."

Jaeger is naturally engaging and extroverted, but much of the credit for making her a "good kid" rather than a spoiled brat must go to her parents.

Roland Jaeger was born in Switzerland, his wife Ilse in Germany, and when they came to the United States in 1956, they brought along a European philosophy of child-rearing rooted in the values of close-knit family life, early teaching of a work ethic and strict but loving discipline.

They taught Andrea and her elder sister Susy -- now 18 and a Stanford University freshman who replaced Goolagong in the Open as a "lucky loser" from the qualifying competition, and won one round before losing in the main draw -- to appreciate life, make the most of its opportunities and not be full of themselves.

The Jaeger parents speak with a Germanic accent, but Andrea's infletion is all-American kid -- pure midwestern twangy and teen-age idiomatic. Every "didn't" is "dint," every "would have" is "wood of" and every "wouldn't have" is "wunta. Much of what she says is wise -- as in "tennis wise' and "schoolwise." Anything peculiar is "kinda weird." At least every other sentence is prefaced by the word "like," and liberally sprinkled with "y'knows."

Nonetheless, she is exceedingly articulate. There is a great deal of native intelligence and keen observation and clever humor in her mile-a-minute, run-on sentences. She gets straight to the heart of a matter and is always honest. She is what journalists call "good copy." An absolute delight. Like compared to Tracy Austin, verbalwise, she's Winston Churchill, y'know.

Jaeger is no shrinking violet, either. She is more of a sunflower, reaching for the light. She enjoys being interviewed, and handles press conferences better than some career diplomats.

Unlike Austin, who considered her early meetings with the media an ordeal. Jaeger looks forward to them. She told a British writer who was astounded at her composure during her first Wimbledon press conference this year: "I don't get up here and get all sweaty or anything. I'm not nervous. yI've been doing it for awhile."

One of the most endearing thing about Jaeger is that she seems to enjoy everything she does. Her grownup woman's success has not interfered with her happy girlhood.

You watch her giggling with her comtemporaries talking about boys or movies or other "girl talk," playing backgammon or pinball, snapping photos with the 35-millimeter camera she won last week but is breaking in gradually "because film is kinda expensive and I dunno if this first roll is gonna come out," and she is perfectly normal 15-year-old.

You would swear that the year of perfecting her game, the traveling to tournaments, the sometimes vicious and ugly competitiveness of modern junior tennis, the discipline, the long hours spent on practice courts instead of at the old swimming hole have cost her none of the verve and joy of youth. They have not impaired her ability to "goof off' and have fun.

Then you watch her on the court, fiercely determined, beating up on experienced veterans, bashing a profusion of hard unerring ground strokes in a back-court style reminiscent of Austin and Chris Evert Lloyd, and you realize that she is their logical heiress: an exceptional talent, a natural who can't miss. And you marvel that she could have reached this level of dexterity so quickly without sacrifincing her childhood, as so many sports and show business prodigies have.

Rosemary Casals said last week, in assessing Tracy Austin after being blitzed by her, 6-0, 6-0, in the second round of the Open, that "to be as good as Tracy is at her age, you must be totally obsessed. It must be a fanatical thing. Tennis must be No. 1, and nothing else in life can come close. Nothing can get in the way: not a movie tonight, not a party. There are very few 16- or 17-year-olds in the world like that."

Andrea Jaeger is not like that, and yet she is better than Austin was at her age, and getting better fast. ("She's improved a lot, just since Wimbledon. Her game has matured a great deal," says Owen Davidson, the former Australian Davis Cup player who is her part-time coach. He offers advice, but says he is mostly retained as her "hitting partner" now that sister Susy is at college and unavailable.)

Whereas their parents sometimes couldn't get Evert of Austin off the courts, Jaeger doesn't like practice that much. "I can think of better things to do," she says. She puts in two or there hours a day because she knows it is necessary, and will play "fun doubles" until the sun goes down or the lights go out, but she considers practice drilling the least satisfying part of tennis.

Asked what is the hardest aspect of the game for her, she said: "Maybe practicing, concentrating all the time in practice, because sometimes I goof off. I'm not real serious and everything. But that might be an advantage for me, too, because meybe then I won't get burned out as easy as someone else. Like if you practice really hard, and run, and do everything you should, then by the time you're 16 you might be sick of it. Even though it's not very good not to concentrate all the time."

She says that she now regards tennis as "work," but only in the limited sense that she has contractual and professional obligations.

"Once you turn pro, it's different. You don't just go to junior tournaments and goof around, wear T-shirts, wear anything you want, go out there and do anything you want," she said after trouching Texas Jeanne DuVall in her first match of the Open on Friday.

"Here, it's a lot different. You're on a contract for something, and you use it. Like I'd never think of going out there wearing anything other than Fila (the clothing line she endorses) -- unless I forgot my clothes, which happened today," she said, explaining that she didn't realize she had a doubles match and brought only one jersey and skirt. They were washed and dried in the locker room, ready for wear in the doubles, even as she spoke.

"Anyway, it's a lot different. But I still have a good time on the court," she went on. "Like when I win, afterwards, it's not like I say, 'Oh well, let's see how much I made this round.' Nothing like that!"

Surely the money she has made so far -- and she is the youngest athlete in the elite stable represented by Mark McCormack's international Managemet Group, which handles her finances and endorsements -- has not gone to her head.

"It's not bad to make money in these tournaments," she said, illuminating her decision to turn pro even though her mother had reservations, "but I'm not going out shopping or buying cars or anything. My dad takes expense money out, and maybe some extra spending money. The rest goes into a trust fund, so if something happens, like if I hurt myself or can't play for awhile, I'll have something left."

Roland Jaeger -- a former amateur boxer, cyclist and soccer player who came to Chicago as a bricklayer, kept that job when he opened a restaurant and lounge, and several years ago became a tennis coach at a suburban indoor club that now includes most of the top Illinois juniors -- preached frugality and responsibility to his kids.

Ilse Jaeger -- who still works part time as a beautician -- reinforced the Lessons. She admits that the prospect of Andrea's turning pro "scared the heck out of me," and she suggested remaining amateur with a view toward possibly playing college tennis. But Roland realized the potential benefits in terms of career development.

"Look, if she plays pro two or three years and decides she doesn't like it, she'll be 18 and can still go to college," he said. "If it works out, she can buy a college.

Roland Jaeger was right -- Andrea will tell you that father usually knows best -- and so after earning a spot on the Avon Women's circuit by winning 13 straight matches, from prequalifying through the title, to take the Avon Futures of Las Vegas in January, she turned pro at Chicago the next week, becoming the youngest pro on the women's tour.

She won one round three, and then beat Casals. Wendy Turnbull and Sue Barker to reach the semifinals in Seattle. She was on her way, and has risen astronomically from nowhere in the computer world rankings at the start of 1980 to No. 8 now -- the youngest player ever to crack the top 10.

Her adjustment was surprisingly easy. Then again, Andrea always has adjusted well to potentially difficult situations, as when she became the only female player on the good boys' soccer team in a tough Chicago youth league. The other players didn't know from tennis, so she had to prove herself as a sweeper and forward.

"At the beginning they were kinda weird about having a girl on the team," she recalls. "When I went out there first, they were going: 'Yeh, well, let's trip her and see if she'll start crying or anything.' Stuff like that. But after that, I was just like one of them sort of."

So it was with the intimidating world of pro tennis.

"When I came out on the tour, I was pretty scared about it -- whether the players were going to accept me, things like that. But now, whenever I'm in the locker room, they always say, 'Hi.' I like being around. Even if I don't play a match I come around and talk to all the players. I feel comfortable. It's not like, 'I can't stay here, because people won't treat me well.' Even most of the men players are really nice to me," she says.

"I think it helped that the first tournament I played was in Chicago, because I was in my hometown and there was nothing to worry about. All the people who worked at the tournament I knew from before. Then I went to Seattle, and beat Rosie and Wendy and Barker, and when I went back in the locker room afterwards they didn't tell the press; 'Hey, that kid's a brat. She should go back home and play juniors."

"They were nice. They just said that I was trying, I was doing as well as I could, things like that. Ever since then, I've felt really comfortable on the tour, because I knew that the players didn't hate me, and that helped me a lot."

Jaeger has fit in so well, becoming a kind of favored little sister of the group, that she refers to such luminaries of the tour as Goolagong and Virginia Wade and Austin by their first names, casually and without pretense, as if she had known them all for years. They don't awe her in the slightest. What appears to outsiders to be her meteoric rise, a rapid series of quantum leaps, seems to her the most natural of progressions.

She has enjoyed the whole experience, including the minibike that has been the chief luxury to which she has treated herself from her winnings, and considers herself lucky.

"I have a really good time. I don't know of many 15-year-olds that ride around on a minibike. They might be going to dances or parties or things like that, but I'd rather play soccer or ride on my minibike or things like that," she said. "I don't think I'm missing out on anything."

Because she realizes her good fortune, she is happy to go out and practice daily, even when she doesn't really feel like it.

"I'm sure that if I was on my own, I could play. I could tell myself to go out there and practice," she says. "Like my parents never pushed me. They encouraged, but they didn't push. And if Susy hadn't always been there to practice, I woulda probably found somebody else. I might have goofed off more, though."

She is grateful for her sister, one of the few players she has never beaten.

They are very close, and even though Andrea is a far better player, there is no jealousy or rivalry between them. It is an interesting relationship. "We'd do anything for each other," says Susy. "I think one reason Andrea cant' beat me is that she is a fighter, she relies on her killer instinct on the court, and against me she has none."

Andrea is also thankful that her parents made their daughters toe the line.

"One of the reasons my dad started us in tennis is that he didn't want us to get in trouble. He didn't want us to go out late at night and like get caught by the cops, and come home and say, 'Well, we didn't have anything to do, so we just went out and broke somebody's window and stole some stuff.'

"He didn't tell us that right out. We started because we had fun. But we realized it later on. And then when a reporter asked him why he started us in tennis, he said it was mostly to give us something healthy to do, to keep us out of trouble."

Andrea Jaeger is still having fun playing tennis, and she's making a bundle. Her only regret is that she misses so much school. "I've always liked school, ever since I started," she says. "Until like fifth grade, I never missed a day. Even if I was sick, I wanted to go."

She will be back at Adlai Stevenson High in about a week, catching up on that geometry, chemistry, history, business ed -- and her forgotten subject: English. Perhaps she will have to do a composition on how she spent her summer vacation. Like that would be interesting, but kinda weird, y'know?