How does Mrs. Van Hopper's treatment of the narrator reflect the true nature of the narrator as the novel progresses?

Mrs. Van Hopper treats the narrator in exactly the way we would expect her to due to the period of time in which the novel takes place. She is American (Americans always seen to be portrayed as loud and obnoxious); she's monied; she's crass and vulgar. In essence, she is everything that a true lady is NOT.

Understandably, our narrator is the woman's companion. Companions generally had no money of their own and depended on their benefactors for everything. The narrator knew her place in Mrs. van Hopper's life, but upon meeting Mr. de Winter and soon after marrying him, she also knew the kind of woman she didn't want to be.

As we see the narrator change during the course of the novel, we also see her carefully avoiding behaviors she has seen in others and has no wish to replicate. Mrs. van Hopper's treatment of the narrator is like a banner that the narrator's true nature is not the "norm" of what people expect She is special, and she has or comes to have her own very special identity.