Question : So I have this friend whom is about to have a baby ... Her bd is really distant & they…

Question : So I have this friend whom is about to have a baby ... Her bd is really distant & they don't talk much at all plus he has a gf who doesn't even know she's pregnant yet her bf / fiancé is incarcerated & they talk all the time , she cheated on her bf & got pregnant but he knows .. Now she's come to the conclusion of giving her baby her fiancés lastname instead of the bd .. Is there anything wrong with that or ???