George and Jeanne Austin of Rolling Hill Estates, Calif., are only one of several sets of parents who are watching their offspring complete at Wimbledon. But they have a distinction. Their daughter Tracy, 15, is the youngest player in the tournament.

Last year, at the centenary Wimbledon, Tracy became the youngest player ever to strike a ball in world's oldest tennis championships. She won one round in the women's singles, then lost to Chris Evert in a match that attracted massive international attention as The Present vs. The Future.

"When she stepped on Centre Court for the first time, we couldn't help but choke a little bit," recalled George Austin, an earnest, scholarly, white-haired and kindly man in his mid-1950s.

"And when she started hitting the ball in the court instead of in the stands, we were thrilled. She seemed totally unconcerned about the surroundings. It was as if she were back home at the Kramer Club, where she plays every day,. She was so nerveless, it was unnerving to me."

Since then, Austin has become one of the top 10 women players in the world, seeded No. 9 in her second Wimbledon. After a shaky first-round match against Californian Diane Desfor, she has played superbly. Today, in the fourth round, she meets No. 2 seed Martina Navratilova, the expatriate Czech whose seven-tournament 37-match winning streak Austin ended in the quarterfinals of the Virginia Slims of Dallas tournament in March.

"It has been a lot different this year. The intrusions seem far less and more controlled. We know our way around, what to do and whom to talk to," said George Austin.

"Tracy has been somewhat on the spot because she was expected to win her first three matches. Although she rarely admits it, I think she flet the pressure. She's been the target and her opponents the underdogs, which is a different psychology. But she handles it very well."

Austin planned long ago to take his vacation from TRW Inc. in Redondo Beach, where he is a physicist in the space and missiles systems division, to watch the two youngest of his five tennis-playing children play at Wimbledon.

The world knows about Tracy. John Austin, soon to be 21, recently dropped out of UCLA to turn pro. He lost in the Wimbledon qualifying for singles, but is playing in the men's doubles with Bruce Manson and in the mixed doubles with Tracy.

"John is big enough to look after himself," said Jeanne Austin yesterday at the Gloucester Hotel, where she and her husband have a room adjoining Tracy's.

"We talk to him a couple of times a day and see him in the tea room at Wimbledon. Yesterday he was tired, so he ate dinner with us, but usually he goes out with the other players. He has friends on the circuit, and spends time with them. We usually order room service and eat with Tracy."

To the rest of the world. Tracy is a tennis prodigy, a marvel of backcourt consistency and poise beyond her tender years.

To her parents, Tracy is all that, and also their youngest, "the baby."

They have to tell her when to clean up her room ("It's full of stuff she can't shut the door"), to do her homework so that she maintains her A-average at Rolling Hills High School, and sometimes even to practice.

"She's becoming more independent, but she still has a hard time making up her mind about anything," said Jeanne Austin. "She's caught in between wanting to be led like a child and to be allowed to make her own decisions, like an adult. She's in that transition period, so we sometimes have to map out her day for her.

"But we're careful not to put too much pressure on her. We try to motivate her when she's down and be supportive. We chauffeur her around, arrange for practice courts, do everything we can for her, but we don't want her to feel she has to win to please us."

"Too many times it's the parents who want their child to be a champion, and that doesn't work. The child himself has to want it, to have the desire and the discipline to make the necessary sacrifices. I don't think you can want anything for someone else."

The Austins have seen far too many "Little League Parents" in their years around junior tennis tournaments - not only with Tracy, who started playing tournaments when she was 7 and has won 17 national junior titles, but with their other children: Pam, 27; Jeff, 26; Douglas, 24, and John.

"It's brutal. Just pathetic. I've seen parents who make their kids afraid to go home when they lose," said George.

"TIt seems to be the same thing in tennis and every other sports," added Jeanne.

"I know of one girl, an ice skater, who lost on purpose in a state competition because she knew that if she won, she'd attain another rung of success and her father would drive her even harder. He wants her to be a Dorothy Hamill, but she doesn't want to be, and that's very, very sad."

Parents trying to live vicariously through their children is one problem, but as George Austin points out, "There is another, more subtle kind of pressure, too. That is when the parents are simply too interested. Not harsh, but so interested that the child feels a burden.

"If Tracy gets a little testy about us being too involved, we back off a little bit. We can sense how she feels day to day, and act accordingly. We don't want to swarm all over her.

"Some parents are at every practice. My wife watches Tracy's lessons, so she can help her understand what she's supposed to learn, but she doesn't hover around, dwelling on every shot."

At Wimbledon, however, virtually all of the Austin's activities are centered around Tracy's preparation and matches, and they occasionally feel like slaves to a fuzzy ball. In the morning it is practice, in the afternoon matches and the seemingly interminable, expectant waits between them.

Jeanne Austin acts as road manager, secretary and confidant for her daughter. She arranges practice courts - a more formidable task than it might seem in London, where they are dear. She gets rackets strung and clothes laundered.

"Jeanne has to seat out the long delays in the dressing rooms with Tracy, and it's been tougher this year with all the rain fouling up the schedule," said George. He appreciates the efficiency with which his wife handles the tedious chores.

"She is very persistent. She doesn't leave any stone unturned. If there is a practice court available within 50 miles, she'll find it and get it organized. A player shouldn't have to worry about the mundane but very necessary aspects of life on the circuit. Jeanne takes care of them so Tracy can concentrate on tennis."

Jeanne Austin didn't realize how many hassles a player could encounter when her two eldest, Pam and Jeff, were playing the international circuit.

Pam quit the Virginia Slims circuit four years ago and became a teaching pro. Jeff dropped off the men's tour last year and has recently finished his first year at UCLA Law School.

"I'm convinced the other kids would have done better in their tennis if they had had someone to help them out," she said. "I think it's important for Tracy."

Of course, the fact that Tracy is so young adds to the anxiety: the others were older when they started traveling the world. Tracy, they feel, is not ready to go no her own.

"Chichester, three weeks ago, was the first adult tournament she's been to without one of us," said George. "But we made certain she was well-chaperoned and taken care of."

The Austins admit that they still get terribly nervous when they watch Tracy play a close match. "I don't think I'll ever get over the sweaty palms," said George. But they were prepared for this, after recognizing early that Tracy had an extraordinary talent.

"She handled a racket very well at age 2," her father recalled. "She grabbed it with two hands and started bashing the ball as well as a tyke possibly could. We gave her a sawed-off racket and tossed balls to her in the living room, and pretty soon she started knocking over lamps."

Her parents are insistent that Tracy has not given up the normal, healthy childhood of which so many prodigies and child stars are deprived.

"Tracy has been a little girl, and she still thinks of herself that way. I think that is why she is so reluctant to turn pro, and we respect that. When and if she wants to start accepting prize money, we will approve, but at the moment her self-perception is that she is a high school sophomore and not a professional athlete," said her father.

"She likes to dink around with her schoolmates. She can be very silly, like any 15-year-old girl. She has enjoyed all the things little girls do. She played so much tennis because there was nothing she preferred to do, not because we made her.

"We do worry about how she will take it if she ever ceases to be a successful as she has been, but that hasn't happened yet. I'm surprised at how graciously she loses, there are usually some private tears for about 10 minutes, and then she's back to normal."