It's My Party (2) - S5.E28

In her quest to become one of the popular kids, Jennifer invites her trendy classmates to her thirteenth birthday party. When they become bored and begin grumbling at her ""lame"" party (which includes a traditional puppet show by her father), Jennifer takes drastic action. With Mallory's guidance, she becomes a ""valley girl"", who then deserts her own party.

Yet, it's only a matter of time before Jennifer realizes she isn't having any fun and she rebels against her new friends.