I think the thing that is most important for you to remember here is that she is showing you who she is right now and it’s important for you to see it. Try to detach from your feelings/emotions for her for a minute and look at the things she’s done, that Anita describes in the post above.  If you were not emotionally attached to her, are those things that you would put up with or would think were okay?

I know exactly how you feel when someone you care about thinks the opposite of how things really are as I’ve been in that position too, but I’ve also had to objectively look at the situation and realize that it was ME who wasn’t being treated fairly, just like she was not being fair to you.

If you can look at this behavior and decide it’s not something you are happy with and she does come back, try not to take her immediately back without question but first make sure that she is willing to work on changing this behavior so that it doesn’t happen again.