We talked last night. She said in the beginning that she was worried me and the X might reconcile, but is not now. We also talked about her past how her X husband was physically abusive and how his family played both sides offering to support her, then turned on her during the court hearings. I did my best to explain why it was important to me to keep a relationship with that side of the family. She stayed pretty calm, but I don't think it has sunk in yet. If it is an issue still, I will just end it with her.
Bingo. So it is very clear that her original stated position has nothing to do with ......... anything. The problem is her past trauma. If we battle with her on whether or not you can see ex-in laws, then you both will lose. If you try to force your case on her, it will do nada to change her past traumas affecting the present.
If you see her as childish, rude, controlling, mean or bad, then it will only hold you back. She is a victim. Empathize with her! Wouldn't physical abuse and traumatic manipulation have a lasting effect on you?
"But that doesn't excuse.........."
You got into a relationship with someone that was formerly abused...... this is the norm. If she becomes the bad guy, then her mind will permanently fix her ex's face onto yours.
This is my "masks" theory, in a nut shell. A similar theory is David Richo's "transferences". It is a psychological reality and it is not like she wishes this trauma on herself. She still has 100% responsibility for what she does in the present moment, but you can greatly help the situation.
This will continue to be a problem for her. It is going to take more than you reasoning with her...... I guarantee it; Psychology says so. There will be other instances that compromise her present self, due to past traumas. It will take you more willpower to be romantically involved with the formerly abused. That is the question you have to ask yourself. Do you have that willpower? Will you learn the skills to be able to handle her when the former abuse strikes her, psychologically?