Slattery is best known as an actor, with credits in film and television including the MGM film Sleepover, and television series including The Jersey on the Disney Channel, The District on CBS, American Dreams on NBC, JAG on CBS, and MTV's Undressed on MTV.
She had a small role in the film Sleepover, in which she played a high school senior named Shelly.
The boys play "Texans vs. Mexicans" at a sleepover at Cartman's house, a game in which the "Mexicans" (led at first by Butters, and then Kyle due to Butters' poor leadership skills) attempt to elude the "border patrol" (led by Cartman) and cross the border into Texas (Cartman's backyard).