Correct, a handgun across state lines requires an FFL even among family members.
Unless you're dead. From that atf reference, #2
"Another exception is provided for transfers of firearms to nonresidents to carry out a lawful bequest or acquisition by intestate succession. This exception would authorize the transfer of a firearm to a nonresident who inherits a firearm under the will of a decedent. See 18 U.S.C. 922(a)(5)."