Stephanie was Jane Villanueva's high school mean girl. The two never got along back when they were teenagers. Stephanie is very smart, as shown when she came up with an elaborate scheme to get Vince DiBacco to go to junior prom with her. She is also very outgoing, and will do anything to get her way.
In high school, prior to her junior year, Stephanie's dad starting dating Jane's mom. However, the two broke up later, and this lead Jane to think this is why Stephanie was always mean to her.
When Stephanie was in her junior year, she had a crush on Vince DiBacco, and wanted to go to the junior prom with him. However, he asked out Jane instead, which caused Stephanie to be upset. She knew that Vince's mom was very religious, so she spread a rumor around the school that Jane's mom was a slut, which got back to Vince's sister. When Vince's sister told her mom, Vince wasn't allowed to go to prom with Jane anymore, so he asked out Stephanie the next day.
In her senior year, Stephanie was still mean to Jane, and hadn't changed her ways. Jane made plans to go to the job fair at her school, but Stephanie changed the time in Jane's planner on purpose, so that Jane would end up missing the fair. Upon seeing Jane's face when she reacted to the fair being over, Stephanie and her friends laughed in Jane's face and left.
Stephanie is seen again at her five year high school reunion. Before Jane leaves to go home, Stephanie approaches her and apologizes for her behavior in high school towards Jane, saying that it "wasn't cool". Jane accepts her apology, and the two start to get along a bit more.
Stephanie and Vince went to the junior prom in high school together. Vince had originally asked Jane to go with him, but Stephanie came up with a scheme that involved Jane's mom to get Vince to go with Stephanie instead.
- Stephanie went through a "social cleanse" last year where she stopped using social media, including Instagram.
- Stephanie dropped out of college.
- Stephanie was part of the drill team in high school.
- Stephanie went to St. Cullens High School with Jane and Lina Santilian.