Yes my mother-in-law's left the house to her Three Sons am I entitled to my husband's part of that estate

You haven't provided nearly enough information for anyone to be able to tell you whether you'd have any entitlement to your husband's part of his mother's estate, and this isn't actually a forum designed to allow someone to answer that kind of question. There are just way too many facts that need to be known. If your husband is living, and his mother left him a share of her estate in her Will, then you likely don't have any rights with regard to that inheritance unless the Will specifically stated that you were being given an interest. If your husband died before his mother did, then whether or not he even gets a share under the Will, and who has any right to receive that share, are completely dependent on what the Will says. In general, it is uncommon for a child's spouse (i.e., you, in this case) to receive any interest in a deceased child's share of an estate. However, it does sometimes happen. The only way to tell is for someone to actually review your mother-in-law's Will and see what it says. If your husband died before his mother and she died without any Will, then you are not entitled to a share of her estate, because by state law only your husband's descendants (children, grandchildren, etc) would receive a share of his mother's probate estate in his place, not his spouse. Your best bet is to consult an experienced probate attorney who works in the state where your mother-in-law lived at the time of her death, show the attorney any documents you have, and provide the attorney with as many facts as the attorney needs to be able to fully understand the exact situation. Best wishes to you.