Ok, so this idea came to me in one of my maladaptive daydreaming moments, but I think it will work.
This idea is that Lisa really isn’t the “good girl” that everyone thinks she is; in fact, she bullied people in her last school and broke up a lifelong friendship. That negative stunt was what really landed her in Greater Johnson Middle School (which was a notorious dumping spot for students who messed up somewhere else), not her parents moving to the city. (I need to figure out which city the story is taking place.)
Now, it’s time to hammer that idea out and see where it goes.