My father in law was hospitalized with alcohol encephalopathy and is unable to walk, stand or make decisions. There is not an advance directive or POA for my mother in law. Does she need one? From what I understand of the law, NJ allows a spouse automatic surrogate status if the other is unable to make decisions. We are still running into issues with being able to manage things without a POA.
Mother-in-law needs to be of clear mind in order for her to understand the legal document. It is best for her to nominate two people to be POA , in case the first person is unable to serve. Sounds like her husband has issues making decisions, thus she can elect her son at first in line, and another sibling, or you as second in line.
Medical Directives are extremely helpful. Both my elderly parents had them, and such document is a guideline when it comes to medical decisions that cannot be made by my parents. I would have been lost without it.
Make sure that both you and your hubby have such legal paperwork for yourselves. It is never too early.