Sadly, it sounds like she has a lot of growing up to do.
On the positive side, if she's looking bad in court that will make it much easier for you to appear the calmer, more reasonable, responsible and the more mature parent. From that point of view she's doing you a favor. Just stay calm, and try to stay emotionally detach (I cannot stress the importance of this). Leaving calmly and quietly when the language or fighting erupts sounds good. (Visualize yourself as a parent with an out-of-control teenager or someone who just happens to be around some mentally ill-stranger.... pull your own personal feelings out of it. I found that made it much easier for me to stay detached no matter what my H said, and I'd even find humor in his words or behavior).
Also, when things were tense or emotional with my H, I would avoid face to face contact, and try to conduct all business through email or written messages, etc...
You might want to consider doing this. But I need to warn you. Keep any and all writing completely emotionless, calm, business-like, and cordial. That way absolutely nothing can be brought into court that can make you look unreasonable. However, if she's writing threatening emails or notes (like saying you'll never see your son) or nasty, ugly things about you or your character. Well... that may be something to keep in a file for when you go to court....
There is no arriving, ever. It is all a continual becoming.
