Keep doing what you are doing. Your demeaner is for you so you can remain detached and calm. Her spewing will probably get worse.
That is what I'm seeing from my STBXW. I have been busy dividing personnel property and fun stuff like that. She can easily make the im a crazy b@tch comment to her parents, sister, son, me etc. Whoever is in the way.
It shows you that the anger is coming from her, through her and until that is dealt with it will continue to be so.
