Jessica Hunter is the secondary antagonist of Dork Diaries by Rachel Renee Russell. .
She is MacKenzie's best friend (Best Fashionista Friend) as well as the second-in-line leader of the CCP (Cute, Cool, and Popular). She also shares her friend's dislike for Nikki and she often tries to help her friend humiliate her. Her hatred for Nikki most likely stemmed from the first book, because she had unwittingly opened a letter that was meant for her.
Jessica was similar to MacKenzie in several ways. They were both rich snobs that were obsessed with fashion and they also acted rudely to anyone who wasn't in their ranks. Jessica also acts like a member of MacKenzie's posse, meaning that she was more of a follower than a leader. This may or may not make her look pathetic.