Fred and Mary Were Married

Fred and Mary were married. Fred had executed a will prior to the marriage that left all of his property, both real and personal, to his mother. Fred later died without changing his will. Mary feels that she should be entitled to some of Fred's estate. While waiting for Fred's estate to be finalized, Mary remarries. Mary's second husband executes a will providing for Mary. Later, after Mary and her husband adopt two children, her second husband dies. Mary feels that her children should be entitled to receive something from her second husband's estate. Is Mary and, later, are her adopted children entitled to receive something under the wills?