I am so sorry for what your daughter is going through. H and I have no children so there is no pain to be cause that way.
It's tough when they cannot see the obvious, isn't it? My H is having physical manifestations of whatever ails him and he looks terrible. Everyone we know in common reports that he is miserable and unhappy. But he's still sailing along on the SS My Marriage Made Me Miserable while I am standing n the dock watching a sinking ship.
I think you are wise and it is admirable to create a safe and loving place for your child and your wife. I think that is all we can do. They have to realize they are not well.
Are you a lawyer, too? I looked back through your threads but could not find any reference to it.