Who is Amy Alice Jackson from Our Only May Amelia and what is their importance?

Amy Alice is the baby Mamma Jackson gives birth to late in the novel. She is named by May Amelia, who chooses her name because Amy is May mixed up and Alice is the name of her favorite aunt. May Amelia is very happy to have a sister to share her life with, tired of always having no one but boys around. May Amelia takes over Amy's care when her mother proves too sick to care for the infant. However, Amy Alice succumbs to what the reader can assume is SIDS only a month after her birth. May Amelia is already devastated by this loss when Grandmother Patience makes it worse by blaming May Amelia for the child's death. It is because of Amy Alice's death that May Amelia spends the winter in Astoria and has a few adventures of her own before returning to the farm.