Sorry, but once they start eating, they usually don't stop. It's a sickness and/or addiction just like drugs. You no longer matter. Your kids no longer matter. The bad role model she presents, doesn't matter to her. She's already ignored her doctors advice, at least once, and probably several times. Nothing YOU can say will do anything except start a fight. Unless you want to spend your productive years caring for a 400# invalid you better divorce her. You will be a horse's @$$. The kids, neighbors, friends, and relatives will all hate you. It's the only option you have. There is always the possibility that the shock of the divorce will get her to regain her health. You might save her life. Good luck, you need it!