She doesn't get to opt out of parenting with you, unless you are like, um, a convicted felon or something.
Do you all not have lawyers? Are these negotiations passing through lawyers?
I can't believe a lawyer is telling her she can do this.
What about mediation? Most courts now order the parties to go through mediation first, especially when there are children.
I'm not sure I understand this process you all are in...
But I will say, get your emotional reaction to what she's done out of it. Don't let that drive what you do next. Her assessment of you as a parent and what rights she thinks you have aren't relevant; it's what she can prove and what the law provides for in the face of that proof.
You are still caught up in reacting to her; instead your focus needs to be on financial and parenting arrangements that are in their best interests and consistent with the parameters of local law.