Well to be fair, people who say "if he's abusing you, just LEAVE" don't understand the psyche of an abused person.

Often times the confidence of an abused person is so shattered that they think they're not worth it or that they deserve the abuse. It's even in the script that Shera says that she deserves what he does to her and it's okay. Not to mention that she might have no where to go or no support system if she did leaves. There's much more at play than simply "she doesn't have to stay".

I'm not arguing for or against the caretaker/cared for suggestion, just saying that if this was a real person dealing with real abuse, it's much more complicated than "she wants to be there".