Seriously. Jess' sister Abby has to be one of the most annoying side characters ever. Every single thing about the character is annoying and destroys the great chemistry the other actors usually have. I can't think of any redeeming qualities, or even a reason why she was even featured in THREE epissodes. She adds nothing to the overall plot. The only thing that happened is that I skip three episodes whenever I rewatch the show. And those three episodes have gotten the lowest ratings of all 120+ episodes.