- For others named Erin, see Erin.
| Character Information
Erin is a girl who vacationed to Little Pwagmattasquarmsettport with her family.
Lisa first met Erin and her friends under the pier. When Lisa casually said hi and walked off, Erin told Lisa that she liked her hat. Lisa took this as a chance to talk to them, then shows them a place where they can hang out, the Little Pwagmattasquarmsettport Public Library. When Erin asked Lisa how she knew about the place, Lisa told Erin that her brother liked going to libraries and she just hung out in front of them. Lisa and Erin then started to bond over their love of just hanging out and not doing stuff. When Bart tried to win over Lisa's new friends with skateboard tricks, Erin dismissed him, saying that his slingshot in his back pocket just reminded her of Dennis the Menace.
When Lisa was showing her new friends a hermit crab and how it moves shells, Erin said that she never appreciated "sea junk" before. Later, Marge let them hang out in the beach house. Erin said that she appreciated it because her mom would be butting in with rice crispie squares and tang by now. Lisa then suggested they have a beach party, which Erin thought was a great idea.
At the beach party, Erin gave Lisa a friendship bracelet which she made. In return, Lisa gave her the shell necklace she had also made from the hermit crab's old shell. Bart then crashed the party and shows them Retrospecticus, Lisa's yearbook, showing her friends that Lisa was a nerd. Lisa then ran off crying.
When Lisa came back from the fair the next day, she found Erin and her friends messing with the Simpsons' car. Erin told the others to hurry up as Lisa would be back soon, before realizing Lisa had got back. They then showed Lisa the car, which they decorated, with "Lisa Rules" written on it in shells. Lisa asked if this meant they were still friends and Erin said it didn't matter who she was, she couldn't fake the kind of good person she is.
Lisa identified Alex as representing "Whatever" among The 20 Types of People You Meet in Elementary School.