Cecily Brooke von Ziegesar ( VON zig-AY-zər; born June 27, 1970) is an American author best known for the young adult novel series Gossip Girl. Early life and education. Cecily von Ziegesar was born in New York City into the Ziegesar family, which belonged to an ancient German nobility from the Margraviate of Brandenburg. She is the daughter of Franz Albrecht von Ziegesar, the CEO and Chairman of Bowne & Co., and his second wife, Olivia James. She is the half-sister of writer Peter von Ziegesar.
https://en.wikipedia.org/wiki/Cecily_von_Ziegesar