* To explain her absence: The son is curious about his sister, who he never knew. The grandmother's story explains that Mary died as a young child, a fact that had been kept from him.
* To comfort him: The story provides a sense of closure and answers the son's questions about his missing sibling. It also offers a glimpse into his family history and helps him understand his own identity.
* To honor her memory: The grandmother's story is a testament to Mary's life, albeit short. By telling the story, she ensures that Mary's memory lives on.
* To highlight the importance of family: The story emphasizes the enduring bond between family members, even in the face of loss. It underscores the importance of remembering and honoring those who came before us.
* To explore the themes of love and loss: The grandmother's story is a poignant reminder of the fragility of life and the enduring power of love. It explores the complex emotions associated with death and grief.
Overall, the grandmother's story is a powerful and moving piece of storytelling that serves multiple purposes. It provides answers, offers comfort, honors the past, and explores universal themes.