How do I handle my mother's erratic behavior in the hospital after her surgical procedure?
It's not uncommon for patients -- especially older people -- to become delirious in the hospital. Just being in a strange environment with disruptive visits by doctors and nurses can be very disorienting. Try not to worry too much about your mother saying she wants a divorce; chances are she's just agitated and confused. Once she gets out of the hospital, she'll be more like herself again.
Meanwhile, you can help her adjust while she's in the hospital. Hang a calendar on the wall, and make sure she can see a clock. Help her understand the hospital schedule -- when the doctor makes rounds, when the nurses will check vital signs, when her meals will be served. Try to create as regular and predictable an environment as you can so that she can reorient herself.