US TV
According to E! News, the actress has been been cast as Lily Van Der Woodsen's older sister Carol in the show, which focuses on Serena's mother as a teenager.
Insiders have described Carol as a sweet character who is prone to making bad decisions about her life.
Previously, creator/executive producer Josh Schwartz revealed that the spinoff would revolve around Lily choosing to leave New York and move in with her sister in the San Fernando Valley.
Carol will reportedly be introduced in an episode of Gossip Girl later this year.
Ritter, who has also appeared in Gilmore Girls, will star in the forthcoming Confessions Of A Shopaholic alongside Isla Fisher.
More: Krysten Ritter, US TV
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