Daughter to a California family doctor, she lives alone in New York -- at 16, a chosen of George Balanchine, grand mentor to a whole corps of dazzling, driven ballerinas. Her speech is pocked with "you knows" and "I means," but on stage, Darci Kistler both articulates and stuns.

"Extraordinary," says her past teacher, Irina Kosmovska.

Darci Kistler's voice is still girlish, the brown eyes warm like those of a lynx in a face that approaches angelic. At first glance, her body looks wispy at 5 feet, 5 inches and 103 pounds; at second glance, you see the sinew of a compact torso, then the hard legs that leap across stages and out of little girls' dreams.

There's a winsomeness to a young dancer like this, a poignancy more intense than that of a young painter or violinist. The artist may create beauty, but the dancer, in an arabesque, becomes beauty.

"During class, she would work like a Trojan horse," remembers Darci Kistler's ballet teacher, "but once in a while, during an adagio, I saw something was happening there. Or sometimes, we'd have them jump and once again, there was this sparkle. Then when she hit the stage, that was it. I told her parents, 'I think Darci will go like a rocket.' But I didn't expect it so soon."

And it's terribly soon, even for a young dancer in a world where the metamorphosis to prima ballerina can occur in just blinks of time. Last week she danced the lead role of Odette in the New York City Ballet's Kennedy Center performance of "Swan Lake." This week she had a principal part in the "Brahms-Schoenbeg Quartet," and tomorrow she is to appear in "Valse Fantasie" at the Opera House.

"Extremely talented," says Alexandra Danilova, the former star who coached her to dance Odette. "A very determined young lady. Once she had a little injury and I said, 'Stop, if it's hurting.' And she said, 'No, no, I will never give it up.'"

Says Darci: "Sometimes I get scared, and think 'Oh, I'm not good enough for dancing.' But then I think, 'we'll, you're doing it, so you'd better try and make the best of it.'"

Listen to her reviews:

"The excellence of her training showed in every move she made," wrote The Washington Post's Alan M. Kriegsman of her role in "Swam Lake," "the carriage of her head, her body placement, the melodiousness of her steps. All the rest -- and it's the rest -- and it's the rest that mainly stamps her as a dancer of awesome artistic promise -- in her own: the natural musicality, the instinctive plastic fluency, the absolute self-possession (in the face of inevitable nervousness) and expressive projection."

This past spring, at 15, she was taken into the company, which very rarely takes dancers before they are 17 or 18. And now, with her appearance as Odette -- the role that's often called the ballerina's "Hamlet" -- she's clearly been singled out by Balanchine, the City Ballet director who has a Svengalian hold on many of his dancers. Over the years, he has singled out and developed such stars as Suzanne Farrell, Patricia McBride and Gelsey Kirkland. Five of his dancers became his wives, and several more were lovers.

Said Farrell, in an interview with Newsweek: "It doesn't matter if the audience applauds me. In the end -- and in the beginning -- it's Mr. Balanchine."

The temperamental, 76-year-old Balanchine won't comment on Darci Kistler, other than to say, "She's my pupil -- I'm working with her." Of him, Darci says: "He helps me, which I love.It's so great that I'm just getting to have him help me with anything, because he knows so much. He's the one who knows everything. He's a genius."

When she talks about herself, as she did the other day in a small rehearsal room tucked away in the Kennedy Center, what comes out is the bewilderment of a 16-year-old perplexed by why she's unfolded so early and fast.

"I just feel good," she begins. "I don't know. Maybe it's just . . . I don't know. I guess, I guess, I don't know. I guess maybe for may age I know a lot. I don't know. I mean, I know it, I just don't know how to say it. It's just, I don't know. I know . . . what was the question?"

But watch her dance. During a rehearsal of Peter Martins'" "Lille Suite" right after her string of "I don't know," the 16-year-old gives way to swan. First, she changes from her maroon practice leotard with the hole in one side into a floating, filmy blue costume a sea mymph might wear. The sparkles on her small bodice glisten.

Even though she's just one of the corps de ballet this time, you can still pick her out from all the figures of procelain. Many of the other dancers look tense and taut-necked, but Darci Kistler grins, as if to dance is to laugh. When it is her turn at the front spot in the row, she flings her face up to the lights, throwing a smile that mixes just a bit of Cheshire cat slyness with a prodigy's pride.

"I don't want to be a star," she insists in the small rehearsal room. "I just want to be a good ballet dancer."

She's from Riverside, Calif., sister to four brothers who wrestled and rode motorcycles. She rode with them, too, and built tree forts. She's been dancing since she was 6, inspired by an older neighborhood friend.

"She was always good," says her father, Jack Kistler. "She's always been serious about what she wanted to do.

"I don't know much about dancing, but I get goose bumps when I watch her. I hate it when she leaves the stage."

Darci's first stage role in California was a mouse in "The Nutcracker Suite"; soon, she had graduated to Mother Ginger and the Los Angeles Junior Ballet. By the time she was 14, she'd been scouted, auditioned and given a spot in the School of American Ballet, the City Ballet's official training institution. Only a year later, she was part of the City Ballet itself.

Naturally, jealousies from others in the 97-member company will erupt. "Of course, there's going to be competition," says Darci. "People saying, 'God, why did she get that part? I've been here longer.' But I just blocked it out. It's going to be that way. You can't think about what other people are thinking."

She dances six or sometimes seven days a week in New York, and tries to fit in five or six hours of practice a day. She lives with only her cockatoo in an apartment on 73rd Street between Central Park West and Columbus Avenue in Manhattan, paid for, via a "good deal," with her $178.46 after-tax weekly pay from the City Ballet. School is almost an afterthought; she's taking a correspondence course from California.

"It's kind of a lonely life for her," says her father. "There isn't anybody really close for her to talk with about problems. It's hard on her. But it's a necessity -- it's either that, or you don't get where you want to go."

Darci herself sees nothing unusual in living alone as a 16-year-old in New York, and nothing unusual in a life centered on glissades and pirouettes. "I'll go out and eat somewhere with friends," she says, "and I'll teach my cockatoo tricks."

But ballet is nearly all. She was moved at 6 by something that almost seems apart from her, a gift given more for her joy than her grasp.

"I liked it because you could just forget about everything," she says. "And just dance."