It does ring a bell. My mother and eldest sister used to say things like 'I haven't got that sort of mind, I can't understand things like that'. If your friend is into denial so heavily I don't think it will help to just come out with it that she's in a cult.
It's a good sign that she didn't round on you immediately and call you an apostate when you suggested reading ex-JW stuff. There is certainly hope I would say.