Don't take this the wrong way. I love my wife deeply and I understand she is not well right now.
I have never had a friend who lies,cheats,steals,trys to control me in every way shape and form,walks all over me If I allow it,has no concept of my feelings,will not communicate,and will flat out throw a fit if something does not go her way. (I am not angry, just pointing out the facts)
I do believe reality hits the mlc'er at times. If she sees me treating her like a best friend through all this I believe she will then see me as weak and carry on with her behavior.
In my case kindness at a distance and being civil is the way to go.