Rosemary Pilkington is a fictional character from the play "The Effect of Gamma Rays on Man-in-the-Moon Marigolds," written by Paul Zindel. She is the daughter of Beatrice Hunsdorfer, a troubled single mother, and is portrayed as a sensitive and intelligent young girl who struggles with her family's difficult circumstances. In the play, Rosemary's character represents the theme of resilience and the search for identity. She often finds solace in her love for science and nature, particularly through her interest in growing marigolds. Her journey reflects the challenges of adolescence and the impact of a dysfunctional family environment.