Sheila first appeared in Rumours and Reputations, Spinner finds an earwig in his cafeteria lunch, but when no one believes him, he decides to boycott the caf and fight fire with fire. In order to prove that there were bugs in his lunch, he collects some of his own and tries to plant them in other students lunch's. Spinner ultimately loses and Sheila the lunch lady punishes him by working as a server in the cafeteria for two months to pay for the cost of extermination the cafeteria now needs.
In Weird Science, Spinner and Jimmy are sitting in the cafeteria talking and Spinner blames his erections healthy food. Jimmy disagrees so they ask Sheila about it. Jimmy asks what kind of food puts a man in the mood. She says that clams are supposed to, but it only gave her husband gas. Jimmy says he means like if she knew a teenage guy. She smiles and says that it's normal, it's only a stage, every guy goes through it. She is referring to Jimmy, which cracks Spinner up.