A daffy and unexpectedly poignant autobiography by the beguiling Balanchine ballerina celebrated in her heyday as a ``rubber orchid.'' Kent, born Iris Margo Cohen in 1937 ``on the very day Edith Wharton died, but in a different time zone,'' repossesses as a writer the unpredictable charm of her dancing. She is zanily elegant, summing up the young Edward Villella's virtuoso hallmark as his ``pronging springbok elevation.'' (And she assesses her own in this way: ``There was a bit of Isadora and mountain goat in my dancing.'') Her life sounds like that of a struggling heroine in a novel by Mona Simpson--frequently stranded, broke, desperate, abused, or abandoned, yet well served by a fey kind of gumption. During a childhood spent in constant transit between east, west, and south American coasts, Kent studied ballet with Bronislava Nijinksa and Carmelita Maracci before entering the School of American Ballet in New York. There she was singled out early, joining the New York City Ballet while still a teenager. Though Kent's narrative bent is too flirty to allow for analysis of Balanchine's work or of her fellow dancers, she shares festively witty peeks at the ballet establishment. Kent also lacks the instinct for sustained introspection, which limits her ability to fathom her family's chronic instability or her own difficult marriage to a drug-addicted, philandering photographer. As a onetime Christian Scientist whose career, paradoxically, was badly, briefly compromised by the effects of amateurish plastic surgery, she is replete with unprobed psychological corners. The story of her losses is at times very painful. Still, Kent can't fail to enchant with her odd tales of artist-friend Joseph Cornell, New York City Ballet colleague Violette Verdy's ``yelp therapy,'' and her own pregnancy (``My stomach was a large, round, hard dome like a planetarium'').