Here's why:
* Elegy Definition: Elegies are poems that mourn the death of a person or lament a loss. They often reflect on the deceased's life, the speaker's grief, and the themes of mortality and loss.
* "Hush Little Sister" Content: While the poem focuses on a sister, it's not primarily about her death. The poem is a lullaby, meant to soothe and comfort a young child. It focuses on everyday comforts and promises of a happy future, not on grief or mourning.
While the poem's gentle tone and themes of comfort could be interpreted as a way to cope with loss, it lacks the core elements of an elegy: a specific death, a focus on grief, and exploration of mortality.