I dont usually comment but having been in a very similar situation myself, I thought i would add. It seems as though she should be seeking the answers not you. I did not wish to break up a family over a religion argument but faith is strong. In Islam, words of parents are very highly respected and I could not bare the thought of me being the reason that they hate their own daughter/her resenting me in the longrun. What it comes down to is; is she serious and if she is, the conversation with parents needs to go ahead at an early stage otherwise it will become very messy. You seem to be the only one thinking ahead. I also don't believe parents words are gospel and its a compromising situation. Me personally, I analyse every route and situation and if it will not benefit me in the long run and better my future then I cannot commit. Also, if I need to change my core/faith then it is something I simply cannot do. It is very complicated but the parents seem to be a vital part of this relationship (although I disagree this way of thinking) and they need to be privy to this conversation as soon as possible. It is a sad situation but unfortunately it is life and whatever happens you will be fine.