Blair Waldorf? Serena van der Woodsen? Let's be real, the best Upper East Side mean girl was always Georgina Sparks on Gossip Girl.

The 'Gossip Girl' star passed away in February 2025 at age 39, and her former cast members are reacting to the devastating loss.

Georgina was played by the actress Michelle Trachtenberg, who was found dead at 39 in her Manhattan apartment on Wednesday. Her performance as the teenage supervillain brought an arch flair to a character who was only a minor figure in the novels that were the basis for the show, but became a fan favorite onscreen.