I think the advise that Resigned and Hopeful just gave you is right on.
You need to protect yourself legally and with an evidence trail in case she makes accusations about you hurting her. She seems to have fallen off the tracks of rational behavior a while ago, and now is capable of saying pretty much anything.
Talk to your lawyer, and find some way to get this done in a public, legal record, backed up with documentation.
I am so sorry that this has happened. Hang in there, you have two daughters to care about and protect.
ShootingStar1