Like I said once she knows there is no more threat, and she knows she has you, she will loose interest again. Oh well use her until she flakes out again.
She needs professional help. You should stay away from her for your own sake. I'm pretty sure you won't do that though.
she wont end her rebound relationship? she doesnt know what she wants. so you need to decide what YOU want. do you want to continue to draw out this painful breakup or do you want to move forward with your life? once you decide to let go, you will start feeling better. but not until you let go.