May be pointing out the obvious but... (spoilers)
I haven't seen anyone mention this on the boards so far, but I strongly believe that Raquelis a lesbian and that that actually turned out to be a large factor in how hostile she treated the other maids as well as Camila. Raquel didn't seem like she really wanted to be gay and felt kind of guilty for it because of her mother or her family which may be why she doesn't like talking about them. She crosses out Camila's face on photos and treats Camila with hatred just to cover up her desire. And when Lucy (the 3rd maid) came into the picture she was treated with similar hostility because she was attractive, and it was only when Raquel saw Lucy naked that she melted and became a soft normal person again. When she embraced her emotions she was a calmer more pleasant person, but when she denied them, she was miserable and hateful. She also seemed to be a virgin when Uncle Eric wanted to sleep with her, and she didn't want to.
This is how I viewed the film, I didn't think it would go this direction. I thought it was going to stay specifically a territorial thing but I don't think that that is the whole picture.
I've come to the conclusion that my guts have *beep* for brains