I just watched Leave Her to Heaven and to be honest, I don't feel she was all that believable. She was different, she had a past consistent with her present, but was she believable? I'd say predictable, but not believable.
I think I know what you mean. She did have a way about her. I think what made it more believable for me is she seemed to just "space out" when the evil took over. Like when Danny was getting the cramp. I'm probably not explaining it too well. I will watch that movie every single time it comes on.
