I am running out of time to find all the facts and the truth. I have to "let her go". That is true for both options I am about to give her. If I have to leave I will and it seems that the one of the conditions in my "plan" will be taking the pets with me.
If she is reluctant to agree to my departure, then the boundary setting makes sense. That would be a whole different situation.
But even with the first choice I can hold my ground and explain exactly why I don't see her fit to take responsibility for what she wants to keep and it does not need to be negative.
If her behavior is caused by her own actions she needs to clean up her act and we can discuss the custody of our pets. If it is health related and beyond her direct control she needs to get diagnosed so we all will know what lies ahead and go from there.