Who is Pearl Miller?

Pearl Whitby (her maiden name, as Briony often forgets that she is now married) is the maid and caretaker of Rose in the house, although it seems to Briony that she does more work with Rose than Pearl, despite not being paid. She cooks for everyone but does not have a large social role in the meals or the family in general. She pops in and out of the story, more or less related only to food.