The down-on-her-luck daughter of a long-dead rock star learns about responsibility and discipline from a joyless moppet who learns how to loosen up a little in Uptown Girls, a film whose gloomy particulars stubbornly resist the cheesy uplift of its plot. Part urban fairy tale, part grim character study about two lost souls, Uptown Girls stars Brittany Murphy as a pampered rock royal whose life of leisure and unaccountability comes to an abrupt end when all of her money is stolen by an unscrupulous business associate. Forced to fend for herself, she gets a job as nanny to 8-year-old Dakota Fanning, a razor-tongued neat freak who treats Murphy with undisguised contempt and behaves like a miniature Anna Wintour. Director Boaz Yakin seems unclear about the tone he wants to convey: In one scene, Fanning chillingly tells Murphy that her father is a comatose vegetable who will soon wither to nothing. In the next, Yakin throws together a wacky montage in which Murphy adjusts to life in the working class. Uptown Girls refuses to make Fanning likable, which speaks to a certain misplaced integrity, and tends to throw a wrench in the film's halfhearted attempts at formula. In Uptown Girls' most poignant scene, a despondent Fanning slaps and punches Murphy before melting into a hug, unable to express vulnerability without mixing it with anger and hostility. Unfortunately, coupled with the phony high spirits the movie demands, that kind of free-floating darkness proves more admirable than effective.