I don't know man, thats tough stuff. She is obviously not legaly bound in any way to her parents. Its interesting that her parents actually like you. I wouldn't know what to do myself...
You could fake her death, and you two could go off and live in paradise. Of course, that probably wouldn't work. I wouldn't do that myself, because I would feel bad about tricking her parents like that. I have a hard time lying to people or tricking them. I always feel bad about it afterwards, so I just don't do it much.
I would say that if she truely loves you, and since her parents actually like you to an extent, you might be able to work something out. Again, that doesn't seem likely to happen either, and like I said, I wouldn't know what to do in this situation.
Good luck to the two of you. I hope you can get this worked out. And by all means, don't just dump her because "it won't work out." If you love each other, I would stay with her for as long as possible.