My mother has advanced Alzheimer's and is in a memory care facility in AZ. Her second husband has chosen not to be around her because of the disease. He lives in a different state, is elderly and in failing health. They have a pre-nup and have kept their finances separate their entire married life. I have POA and have handled my mother's finances for the past several years. I want to protect my mother from obligations her husband might incur including health care costs that outstrip his ability to pay. Do I need to file a divorce action, or is a legal separation adequate to protect her?