Her brother, Dewey, is a police deputy with the Woodsboro police department. They get along like you'd expect a brother and sister to. Tatum is constantly making fun of Dewey, and not just at home. She even picks on him in front of everyone at the police station. But you can tell that they care about each other.
Tatum and Stu have been dating for awhile. Stu had dumped Casey for Tatum (or maybe Casey dumped him for Steve) and they seem to have a good relationship. Except when Stu is acting like a moron and Tatum has to keep him in line.
Tatum is a great friend, and a really cool girl. But sadly, in the grand tradition of horror movies, this makes you a victem. Let's just hope that Tatum can take care of herself as well as she takes care of Sidney.