The love between two half-sisters, 21 years apart in age--delivered in the generally upbeat, flip, feelings-talk style of trendy Manhattan. Freelance artist/photographer Ingrid, settling into work and dividing bedroom time between Mickey and Matthew, is happier than she ever remembers being. But then--after Vermont Christmas with her father, his second wife, and their small child Stephanie--Ingrid learns that father-and-spouse have been killed in a car crash. And she is now guardian of her half-sister, ""a long little girl. . . combining in one head a Breck shampoo ad, Fred Astaire, me at the same age, and the Plaza Hotel's Eloise."" Why does Ingrid accept the guardianship and take eight-year-old Stephanie to New York? Well, she's had one abortion and can't face rejecting another ""unwanted."" But once in N.Y. with Stephanie, Ingrid flounders--snatching work, friendships, and identity around Stephanie's needs. She also has the giant headache of dealing with a folksy Vermont lawyer, who prods her into the legal/social-worker complications of guardianship and unfolds the tiresome details of a car-crash-related lawsuit--which will wipe out any inheritance. As for bright, resilient Stephanie herself: she discovers that her best friend in Vermont has found another; schools (two of them) often stink; Ingrid makes her continue violin lessons; and, worst of ali, Matthew--whom Stephanie adores--isn't really into family and cops out. Eventually, however, Stephanie, adapting to the Big Apple, worms and all, simply becomes Ingrid's kid. . . while Ingrid makes some choices--tossing out a selfish new lover, learning about love and family from Stephanie's grandfather in Boston (who's fighting for his space). And Matthew, loving them both, comes back to start over. Convincing kid-talk, glib adult gab, and a glossy Manhattan backdrop: a likable, Judy Blume-ish story with adult-reading sex but YA appeal.