Everyone came to the wedding, including a distant 'cousin' no one had heard from in years.
He's her 'first cousin'. = He and she are 'first cousins'.
He says politics and show business are 'kissing cousins'.
(..) You're a Parselmouth? Why didn't you tell us? -l'm a what? -You can talk to snakes. l know. l accidentally set a python on my cousin Dudley at the zoo once. Once. But so what? l bet loads of people here can do it. No, they can't. lt's not a very common gift, Harry. This is bad. (..)2002 Harry Potter and the Chamber of Secrets