(This is Stan's POV so you are Stan)

(And she is also aged up so she is 18)

Wendy Testaburger is a major-supporting character and the most prominent female character on South Park. She is the most prominent of the female classmates of Stan, Kyle, Cartman, and Kenny, as well as Stan's on-and-off girlfriend. Wendy is a female fourth-grade student at South Park Elementary. She made her official first appearance and first official speaking role in the Season One episode "Cartman Gets an Probe". Wendy has been voiced by four people during the series' run: Mary Kay Bergman, Mona Marshall, Eliza J. Schneider and currently April Stewart and in this AU, she is your Big Sister