My question involves collection proceedings in the State of: Florida

My mother never signed any medical treatment agreements or anything with the hospital in regards to my father's cancer treatment. He has recently passed away and the hospital now wants to collect the remainder from her. His will left everything to her so there is nothing to go to probate. My questions are these: Is she still responsible for any of his medical bills because she was his wife, and if not, is there a statute that states this? Also, is there anything she should do, i.e. writing a letter to the hospital or debt collections, stating this?