NEW YORK - Beyonce has a stepmother. Her father and former manager, Mathew Knowles, got married last Sunday. His representative told The Associated Press on Friday that he has wed former model Gena Charmaine Avery in Houston, Texas. The pair had been engaged for a year and a half. The 48-year-old Avery is a realtor. The 61-year-old Knowles guided his daughter to superstardom.