She is first mentioned by Finch when he reveals she bailed him out of jail for stealing the motorcycle of his boss when he did not receive a raise he was promised.
She later appears at the East Great Falls high school reunion to pick him up and meets Paul's frenemy, Steve Stifler. Seeing this as his chance to finally get revenge on Finch for all the times he had sex with his mother, Stifler becomes acquainted with Rachel. While conversing on her time in high school and how she wished Paul was more into sports, she makes a brazen sexual pass to Stifler, which causes an awestruck Stifler to declare that he loves her, and proceeds to have sex with her on the lacrosse field, where Rachel loudly and passionately agrees with Stifler's proclamations about his manliness. John and Justin (the two MILF guys) happily chant MILF at the sight of Stifler and Finch's mom having sex. When Stifler calls her son a dork, Rachel angrily (and passionately) tells him to stop talking bad about him. She is then heard making a loud scream, implying an orgasm had been reached.