I am not so sure I would "get out" but, I certainly wouldn't pop the question. Maybe you just need to regroup and think of the relationship on a different level. If you are truly only the second guy she has dated then she really isn't ready for marriage no matter how she feels right now. You can bet at some point she would start wondering what it is she missed out on by not dating more and you will both wind up hurt.
Just my 2 cents whatever that is worth these days
