In your situation, I wouldn't either. My H and I have a cordial relationship but if/when it comes to D, I will make sure that I let the lawyers do the lawyering. My H is a nice, fair man but I know he will make sure his best interests are taken care of, as we both should.
Try not to judge what she's doing and sit back and let the lawyers do their jobs. What you see as nasty, someone else might see as making sure her best interests are taken care of. Even you admit that you don't know who is instigating the tactics. So some things were changed and they could change back. I think it's all part of the game of negotiation.
Don't take it personally.
Me 57/H 58 M36 S 2.5yrs R 12/13
Let me give up the need to know why things happen as they do. I will never know and constant wondering is constant suffering. Caroline Myss