Who is Sherry Kolarik from Spencerville and what is their importance?

Sherry Kolarik is a waitress at the diner in Spencerville where Cliff Baxter often has breakfast. She had a couple of traffic tickets, and when Cliff came to her door and told her to pay or he would arrest her, she offered sexual favors instead. The couple then embarked on a long term affair in which Cliff Baxter often forces himself on her.