Television, doomed or just destined to be the supplier of everything, even delivers babies -- national surrogate children who grow up, and then old, before our eyes. Of all of these, few have been as absolutely lovable as Kristy McNichol, who has now committed the tantalizing indecency of turning 18 and who threatens to go all adult on us at any moment.

"I'll never mind being called 'cute.' No, never," she says, in her baggy pants and baggy top, her red socks and white tennies. Her hair is wet and scraggly and it's too early in the morning for civilized conversation, but those two walloping brown eyes of hers are as much a pair of heart-melters as ever.

"I thought I looked funny when I was young. I probably still look funny-looking, but not as much, maybe. Everyone says my eyes are my best feature, and I'll agree to that. I don't like my nose. I think it's too fat on the end. Right here. Edspecially when I smile; it gets even bigger on the end when I smile."

She smiles to make her nose look fatter and laughs at having smiled.

Kristy is a California child. At the age of 8, she and her brother Jimmy started doing commercials in Los Angeles where her mother, divorced from her father when Kristy was 3, was working as a secretary and a movie extra. Eventually, Kristy did "20 or 30" commercials and then was cast in some of ABC's excellent, trailblazing "Afterschool Specials."

At the age of 12 she landed the part of Buddy on ABC's "Family," the only half-intelligent Spelling-Goldberg production ever made, and remained with the show through its four sensitive seasons. Then, puberty became irrefutable; America's little girl played a tough-cookie teen-ager in "Little Darlings," an awful movie about two girls at summer camp who make a bet on which will lose her virginity first. Kristy, uh, won the bet. She also stole the movie from her pudgily dissipated costar, Tatum O'Neal.

And she moved into the ranks of such illustrious mollycoddled lolly-toddlers as Brooke Shields and Mariel Hemingway, but with an accessible, no-nonsense, down-to-earch quality that is enviably her own. She's not the pouty model type but rather a slightly boyish girl-next-door who takes no guff and gives none.

Now she is starring in "The Night the Lights Went Out in Georgia," based on a long-dead top-40 tune and opening throughout the country early next month. To say that Kristy McNichol, now 18, is nonchalant about her fame and good fortune is not just putting it mildly, but scarcely putting it at all. She is unfazed, un-flapped. She rattles on merrily past the 55-mph speed limit talking about her likes and dislikes like any other 18-year-old girl and, like an ordinary American teen-ager, proves herself entitled to the view that the world was put here to give her something to do.

"I believe in God, and I believe in being a good kid and nice things will happen to you in life," she says. It's hard to stifle the old sighs when you're in company like this.

It's also hard, upon entering her hotel suite, not to notice a young man clad only in shorts bolting into another room. Later another young man who wears leopard shoes and a leopard belt emerges from another room. This turns out to be "Joey," Joseph Corsaro, a hairdresser about whom Kristy has been "kind of serious for the past two years." The other boy was Mark, who is traveling with Allison who is traveling with Kristy.

Oh, those Slinkies and Barbie Dolls have long since been put away. Kristy has gone and grown up on us. Bad enough that "Little Darlings" was all about sex. The ad campaign for "Georgia" features a drawing of Kristy in short-short cutoff jeans with one bare leg leaning on a post; she looks seductive as all get-out.

"I like that picture. I think it's neat," she says, sounding both ingenuous and businesslike, "I didn't think it looked sexy. I thought it looked really cute. I don't look at myself in a sexy way, 'cause I'm never trying to be that way. I hope people don't think I'm trying to be sexy and this New Thing and, 'Come see me with my hot hot shorts and my boots on,' 'cause all through the movie there's only one scene where I wear those shorts and those boots."

"Little Darlings" was widely criticized as part of a seemingly growing reliance on young girls as sex objects. Kristy sees the movie, which opened with her kicking a would-be suiter in the groin, as having been innocent if not innocuous. "I thought it was a fun movie, I really did. I thought kids my age could really relate to that movie. I don't know what's shocking about it. I didn't think of it as a sexy movie, 'cause the only thing I did that you saw on the screen was kissing him [Matt Dillon] and talking with him. That's it.

"So I didn't consider it AT ALL exploiting or provocative. Or shocking. It is what normal teen-agers talk about nowadays. And even younger than that! Even younger kids know more than that. None of my friends thought anything of it, they knew all the stuff that was going on. You know. And even more. I've seen kids that are 12 years old go down the street and they're on drugs.That's real sad.

"I think it's neat that the movie was rated R only 'cause a lot of kids my age wouldn't want to go see a PG movie. If you take "Tatum O'Neal and Kristy McNichol' and put 'em on a poster and it's an R-rated film, people will say, 'Oh well, let's see what goes on in this R-rated film with them two.' See, the whole idea was to get everyone in to see this movie thinking they're gonna see a whole lotta STUFF. But they didn't."

Kristy says her agent gets lots of offers but turns down more than half because he knows the material is unsuitable. She is asked what sorts of things he rules out. "Nudity probably at this time," she says matter-of-factly. "And a lot of foul, foul language, a lot of it -- I mean, heavy . Nudity? It's not that I won't. 'Cause I saw a movie called 'Coming Home' and I thought the scene in that was one of the most beautiful things ever shot. But then again I've seen movies where they're very tacky."

Whether she would do a nude scene (and the interviewer is not ) pressing her on this, so get that thought out of your head) would depend on how much "control" she had over the shooting, Kristy says. She also complains of a photo on the cover of lowly Us magazine that she lacked "control" over it. Kristy McNichol has been in The Business long enough to know how important CONTROL is. She's a pretty in-control little cookie.

"That 'Us' thing," she mopes. "They had a terrible picture and they put it on the cover, and the cover was also a lie. They said, 'Kristy Sheds Her Tomboy Image for a Live-In Lover.' I have a house that I live in with my aunt, and my boyfriend lives a little bit over the hill. And they picked out a kind of tacky picture, me in a kind of dance position and the shirt was kind of low -- I mean, nothing was showing, or anything, but the skirt was real low -- and I'm going [she spreads her arms and makes a goofy face] and I really didn't have any control over it."

Nor does she have any control over fans who so besieged her with telephone calls that she and her family finally arranged a system whereby only one employe of the phone company knows her number. "There were people from the phone company giving my number out to their friends! There was this guy that met me in a disco who worked for the telephone company who gave it to his girlfriend, so I get a call in the middle of the night: 'Hi, I just thought I'd call.' It can get to you."

Yet she does not begrudge the press a certain amount of prying into her life. "I think the public deserves to know what's going on, 'cause they're the ones that made me what I am today," she declares sternly. "For instance, they deserve to know what kind of car I drive, who I'm seeking, how my parents and my brothers are getting along in the world, how's my dog, those kind of things. I understand perfectly that the public should know and I don't mind telling at all."

She drives a red Fiat Spider but also has a Jeep and a Jaguasr. She's seeing Joey, the hairdresser boyfriend who moved to L.A. to be near her. Her mother remarried a year ago and Kristy likes her stepfather a lot. Her brother Jimmy just completed a thriller called "Mama's Boy." Her other brother Tommy is not in show business but is "heavily into computers." Her dog is fine.

Also: She has seen "Raiders of the Lost Ark" four times, doesn't like to sit in the center of restaurants "'cause then I know everyone's watching me from all angles," hasn't eaten Kentucky Fried Chicken in nine years because she got sick of it during a three-day commerical shoot for Col. Sanders, and says of television, "I don't think anything on TV right now is worth watching. Except "I Love Lucy.' And the news. That's it." n

After completing "Georgia," she did another film, "Only When I Laugh," which Neil Simon based on his flop play "The Gingerbread Lady" and which naturally, start Simon's wife, Marsha Mason. In September, Kristy goes to Australia to film a new version of "The Pirates of Penzance," inspired by the successful Broadway revival. Kristy will costar with Christopher "Blue Lagoon" Atkins, whom she insisted on meeting before signing the script and found to be not a stuck-up snob at all. Can you beat that?

This may not turn out to be Gilbert and Sullivan's "Penzance," however. "They're changing it to more contemporary music. It's not going to be anything like the play." Suddenly, to her nearby boyfriend, Kristy murmurs a husky "Grimme another drag, Joey," sounding like Ida Lupino at her most macho. "It's not gonna be so old-fashioned," she continues after the puff from a Marlboro. "We're cutting all that [sings soprano] uh -- HAH-ha out. It's really campy and fun. I mean, young audiences don't get into the play "Pirates' and I don't think they'd get into the movie if the movie was exactly like the play. Because -- [she turns her head and flashes her get-serious look] it is very boring. I went in there and I almost fell asleep. I was bored.

"In our version, everything's exaggerated." On the word "exaggerated" she waves her arms and rolls her eyes and turns into Times Square for a split second. Then she slumps quickly back into nitty-gritty. She's a nitty gritty girl.

Yes, still a girl, still a girl, but only by a hairsbreadth.

She does not ever wish she had not become famous and an actress.

"'Cause I would never be able to relive the things I have just been living in the past 18 years. I think it was perfect. I think everything's perfect. Almost too perfect. My life is too good right now, and people don't understand -- 'Come on, there's gotta be something wrong somewhere.' No. Everything's fine. And no one will believe that.

"If my career continues the way it is, I'm gonna continue it. There's no way I'm gonna stop for anything, 'cause I love it so much. I think I'll just continue growing up in front of everybody.I want to be like a young Jane Fonda when I'm 25 -- in acting, that is. I love her. I like Sigourney Wiener too -- Weaver," she adds, correcting herself.

Be a good kid, and nice things will happen to you in life. "In 10 years from now, 'll maybe have a few kids and do one movie a year. And live in a nice area with clean air and on a nice big ranch with a lot of animals. Horses, dogs, roosters and cats. You know, cock-a-doodle-do at 5 in the morning. I don't think about money as much as I think about living well, eating and having a nice place to live in, having good friends and family and working and just enjoying life to the fullest.

"'Cause," she says soberly, "life is already too short."