Retirement life insurance.

Hi, My brother recently passed away and he is married to a woman for less than 5 years. They have been separated for 2.5 years (not legally) after she found out he needed a leg amputation. Nobody would take care of him, so I, his youngest sister, stepped in and got power of attorney and health power of attorney to help him make decisions til he could get his right senses back. The anesthesia from the leg amputation, made him off his game for a while, but he came back for most part but stayed in a nursing facility. He got medicaid while he was there and less than a year the nursing facility sent him to a hospital for medication review and then next day packed his things and said they did not want him back. He ended up staying at the hospital for 180 days, and then went to hospice for 2 days and passed away. He has a life insurance policy he had gotten from his work years ago, for $10,000 and had put me as beneficiary so that he would know he would get a proper burial. Now, after 2 and half years not knowing where wife went or even if they were really married, I have taken care of funeral arrangements and now she is getting a lawyer to go after his life insurance. We are in the state of Ohio. Would appreciate if you could tell me what I need to do? Thanks in advance