The Nanny Diaries (2007)

Twenty-one-year-old Annie Braddock has just graduated from Montclair State University. She has no idea what or who she wants to be. One day, while sitting in the park, Annie sees a young boy about to be hit by a vehicle. Annie saves him and meets the boy's mother, who we meet as Mrs. X. When she introduces herself as "Annie", Mrs. X mistakes her words for "Nanny" and hires her to look after Grayer, the boy she saved. Annie lies to her mother about taking a job at a bank and, in reality, moves in with the X's to be the nanny for Grayer.