Ms. Sharon Norbury is the 12th grade calculus teacher at North Shore High School, portrayed by actress Tina Fey. She is the coach of the North Shore Mathletes. Sharon bartends a couple of nights a week down at TJ Calamity's in the Old Orchard Mall. Her first encounter with Cady Heron began on Cady's first day when she bumped into Sharon and spilled her soda all over her shirt. Ms. Norbury proceeded to take her shirt off, but at that time, Mr. Duvall walked into the class to see if she was okay; her shirt was stuck to her sweater and she ended up revealing her bra in front of the principal. In the movie she tells Mr. Duvall about her revent divorce with her ex-husband (whose name was never revealed). Throughout the movie principal Ron Duvall seemed to have a crush on her; by the way she smiles at him when they dance together at the Spring Fling it's possible she feels the same way. Prior to that, the only guy that ever called her house was Randy, from Chase Visa.
Ms Sharon Norbury is a "successful, intelligent caring graceful young woman," according to Duvall and explains to the girls that putting someone down won't make you happier, and calling each other sluts and whores just makes it okay for "guys to call you sluts and whores". Ms. Norbury does not appear in Mean Girls 2. It is possible she left to work at a new school; it is hinted that she is married to Mr. Duvall due to how in Mean Girls 2 Mr. Duvall is seen with a wedding ring on his finger.