Uptown Girls (2003)

Molly Gunn (Brittany Murphy) has never worked a day in her life and has lived like a queen since her father, a famous rock 'n' roll star, died and left her his fortune. But everything changes when Molly realizes that her manager has stolen her money. She lands a job as a nanny for Ray (Dakota Fanning), a young girl whose serious attitude is the opposite of Molly's carefree one. With help from her boyfriend, Neal (Jesse Spencer), Molly tries to bond with Ray and learn how to be an adult.