Nettie

Nettie is an interesting character. Her character and role in the novel is weaved very cleverly into the story. She is nothing - a mere side note of description - for the majority of the novel. But at the end, we see that the side note was really a major hint. Her role is huge. Her character and her actions practically change the course of the novel. She is the only source of comfort for Lily. Lily hallucinates about her experiences with Nettie as she's dying. It's amazing how Wharton uses characters to manipulate the plot - even seemingly minor characters like Nettie.