Upon turning eighteen, Joanna Maitland flees the stifling upper class existence of her Boston home and the guardianship of her stern aunt Katherine to visit her mother Millie in Palm Beach, Florida, the mother she has been forbidden to see by the terms of her father's will. The snobbish Maitland family has deemed Millie, a woman from "the wrong side of the tracks," to be an unfit mother and has threatened to withhold Joanna's inheritance unless she repudiates her mother. In Palm Beach, Millie earns a precarious livelihood catering to social climbers, and is currently in arrears on her hotel bill. Katherine, concerned about Joanna's welfare, dispatches Robert Lattimer, the son of the Maitland family's late attorney, to bring her home. Arriving in Palm Beach before Joanna, Lattimer warns Millie that a violation of her custody agreement could result in the forfeiture of Joanna's inheritance. Soon after, Joanna appears at her mother's door, and although Millie pleads with her to return home, explaining that she wants to spare her the humiliation she must endure as a "ladder for social climbers," Joanna insists on staying. Upon learning that her mother is penniless, Joanna introduces her to the social-climbing Mrs. Sarah Harris, whom she met on the train to Florida. Millie convinces Mrs. Harris that in order to be welcomed into Palm Beach society, she must sponsor a ball to benefit the pet charity of Mrs. Cooper Austin, a local dowager. After Mrs. Harris eagerly writes a check for $20,000, Millie persuades Mrs. Austin to lend her name to the ball, and Mrs. Austin agrees on the condition that Millie write a check to the charity's bank account. Joanna, meanwhile, confides her family problems to Lattimer, and although he is sympathetic, he maintains that she must return to Boston. In arranging the ball's details, Millie secures commissions from the florist, costumer and jeweler. From the jeweler, she also borrows an expensive diamond necklace for Joanna to wear at the event. With her commissions, Millie is finally able to pay her overdue hotel bill. Lattimer, who has fallen in love with Joanna, convinces Katherine to allow her to attend college. When Millie refuses to help him persuade Joanna to return home and finish her education, he accuses her of being selfish. On the day of the ball, Mrs. Harris' husband Henry stops payment on his wife's $20,000 check. When Joanna turns to Lattimer for the funds, he accuses Millie of trying to ruin her daughter's life. To protect her mother's reputation, Joanna pawns the necklace to cover the check. Upon learning of Joanna's larceny, Millie embezzles the funds from the charity's bank account and buys back the necklace. Then, to teach Joanna the futility of trying to earn "easy money," Millie impersonates Mrs. Austin and reports the embezzlement to the police, finally earning Lattimer's respect when she confides that she arranged for her own arrest to teach Joanna a lesson. When the police come to arrest Millie on the night of the ball, she pleads with Joanna to depart with Lattimer and thus spare her the humiliation of having her own daughter witness her arrest. Happy that her sacrifice has saved her daughter from following in her footsteps, Millie leaves the ball in police custody.