Move on. I've seen it before. Every time the BF scews up, she'll come to you. After a few months, she'll be back with BF untill he screws up again. This cycle will go on for as long as you let it. If he screws up bad enough, she may even agree to marry you. The divorce will happen a within a few years when you find out she is cheating on you with him.
Unfortunatly, while you feel she is the one for you, she does not feel the same for you. You cannot make someone love you. You need to find someone who already loves you, they may just not know it yet.
OK, this is where I the women start flaming. While you are looking for Miss Right, have some fun with the Miss Rightnows. Not everyone you go out with needs to be the one, sometimes you can just have a good time.