Read the passage and find the corresponding person for the given pronoun. The word between ** ** is the target pronoun.
Q: When his obsession with Katie and her boyfriends reaches extreme limits, Janet suggests that Doug needs psychiatric help and he seeks out an expert who gives him advice that goes wrong whenever it is applied. Throughout the latter half of the film, Katie has three boyfriends, two of whom she eventually stops dating. At the end of the film, Katie takes a class trip to Europe and reunites with Richard again -- at which point Bonnie, **her** younger tomboy sister, begins her own dating spree.
A:
Katie