BM, this is nuts. You HAVE taken ownership of your part. You've shown her that in every 180. And in GAL. And even in detachment, which you have been pretty good at.
This is typical WAW/WW history rewriting. My guess is that she is wavering again on her insistence that it is over. After all, why belabor the point unless it is in order to convince her self? She knows you own your part, this is her excuse for continuing her wayward behavior.
Just ignore it and keep doing what you are doing. She may file. She may not file. You have no control over that.
I forget, where does the mediation agreement stand? Is it still enforceable?
M(53), W(54),D(19) M-23, T-25 Bomb Drop - Dec.23, 2017 Ring and Piecing since March 2018