Hapsy is the youngest, and apparently favorite, daughter of Granny Weatherall. She has two other daughters, Lydia and Cornelia. Hapsy, though, also seems to be the biggest disappointment to Granny (eNotes). Granny keeps calling for Hapsy during the story, but she never shows up at Granny's deathbed. Granny also confuses her other daughters for Hapsy in her delirous state of mind (eNotes).
This vision of the Hapsy holding an infant contains much religious symbolism:
Granny "seemed to herself to be Hapsy also, and the baby on Hapsy's arm was Hapsy and himself and herself, all at once, and there was no surprise in the meeting." Some critics have interpreted this memory of Hapsy as the sign of salvation that Granny seems to be looking for throughout the story.