Selectively reading what you want and basing your advice on that is not the best way to go about solving a problem.

I am Not saying “hey OP go over sleep at his house”, I am saying over time... with help and counseling perhaps. She’s still allowing home to see the kids. No cps,police, social services have been involved as far as I have read. If she’s happy then yes end it all by all means but if she’s saying things like he was a caring person, love of her life, etc then perhaps maybe with a lot of help there can be something. Using your logic im going to go around telling anyone with a SO that is depressed, bp, mentally ill should drop them, regardless if it can be fixed or not. I’m Thinking long term and only ifffff we don’t ignore the other half of what OP stated. But for now yes she shouldn’t be near him.