Nanny, in Paul Zindel's The Effect of Gamma Rays on Man-in-the-Moon Marigolds, plays a rather secondary part. Her importance lies in what she symbolizes.
Nanny is an old woman who is a boarder in the Hunsdorfer home. Beatrice Hunsdorfer agrees to take care of the old woman (who is almost blind, cannot walk without the aid of a walker, and deaf). Nanny's daughter refuses to care for her. Nanny must depend upon others to survive. Her role represents a sad and lonely end to life.
Nanny represents solitude and despair. She acts as a reminder to Beatrice that it is possible for one's family to turn on him or her, leaving the person alone and broke. Tillie, Beatrice's daughter, sees what can happen to a person if left alone. For Tillie, Nanny represents everything she does not desire to become.