Who is Miss Brewster from Leaving This Island Place and what is their importance?

Miss Brewster is the head nurse at the almshouse, where the narrator's father lays dying. The narrator describes Miss Brewster as ".... old and haggard. And she looks as if she has looked once too often on the face of death; and now she herself resembles a half-dead, dried-out flying fish, wrapped in the grease-proof paper of her nurse's uniform."