I am sorry for the death of your husband. What needs to be done is to determine who actually is the owner of the property. Her stating it was your husband's and even her paying him hush money does not legally make it so. Even if he is the legal owner, she may have gained an easement or some other right against the property.
I assume you have started the probate process for your husband as he seems to have had more than $100,000 in asets so must go through probate. The person appointed administrator by the court will go into the issue of who owns the land, but you should watch over them very carefully since they may not do the best job in making that determination and also finding out how much back rent is owed. It wil help you to read some of the books available on probate, such as the Nolo Press ones, so that you know what should be done. You can ask the court to be appointed the administrator and then hire at the estate's expense [which is really yours] hire an attorney to find out about the property [but it is much cheaper to have someone else do as much work on that issue as possible].
Good luck.
[not proof read]
