So why have you not set boundaries yet about the partying?
When she makes a false accusation, you just nod. At most you can say I don't see it that way, I'm sorry you do, it's obviously causing you angst. Or something like that, but you can't defend yourself because she's not going to be convinced of anything.
Eventually, she will come to her senses....you just have to decide if you have it in you to hold on.
