I think we can all agree that legally speaking, we need more information to say one way or another. I really only take issue with your first comment where you say FIL "will win". I mean we don't have the "contract" and have only "facts" from the party attempting to assert a contractual relationship. The need for skepticism should be obvious. The onus is on FIL to prove that relationship. This onus is a heavy one because it directly conflicts with MILs stated intention by designating her beneficiary.