Nancy
Nancy is Bill Sikes's partner. Although it is never directly stated in the novel, many critics have suggested that Nancy is a woman of the night, a prostitute. We can guess that she may be in this profession because of her constant references to the fact that her station is unchangeable: a Victorian belief held about women and purity was that if you were taken (lost your virginity) there was no hope for recovery. Society would cast you aside forever.
Despite being part of a world of criminals, Nancy is a person who cares deeply for those surrounding her, especially Oliver and Bill and, like Oliver, is prepared to put herself at risk for others. Nancy's death in the end is, in a way, the only thing that saves her as it puts an end to continual physical abuse and allows her to escape a society which is constantly condemning her.