Mary-Beth Williams
Mary-Beth Williams is the new born baby of Louise and Marty that appeares a few times in the game. It is thought that after both her parents die her aunt Mary-Jo takes care of her. She is the only minor to appear in the Grand Theft Auto series. She is seen briefly being cared for by Louise Cassidy-Williams in a Blue Hawaiian Blanket which is similar to that of Tommy Vercetti's street shirt, which he wears at the beginning of Grand Theft Auto: Vice City.