William Larkin is the brother to Theresa Russo, Ernesto Larkin, and Janeive Larkin. He is the son of Magdalena Larkin and Mr. Larkin. He has a brother-in-law, Jerry Russo, who is also Theresa's husband. He has 1 niece, Alex Russo. William Larkin also has 2 nephews, Justin Russo and Max Russo.