You need professional legal, medical and social advice.

I cannot imagine how to untangle this problem and also maintain strong relations with your wife. Aside from the (easy) opinion, above, I think your first duty is to your relationship with your wife and all other relationships are secondary. So in furtherance of that goal, I would encourage and support your wife as she makes the decisions concerning her parents. Perhaps if she had legal, medical and sociological advice to guide her, your support through these difficult, heartbreaking struggles would be golden to her.

Kerry, that is a tough, tough situation. best of luck.

B