"How else do you cope...?"

Sounds like she is not coping well at all. In addition to the above advice, I suggest that she consult a therapist to learn some coping skills and stress-reduction techniques. She's directing all her stress inward and it's obviously self-destructive. She might take up yoga or tai chi or some such, too.

What is preventing her from resigning if she wants to? It might cause some economic hardship for a time, but it would be healthier for both of you stress-wise, which in the long run would mean lower health-care costs. If she's holding out so she can sue for wrongful termination, then document, document, document.