The Gossip Girl actress was found dead in her apartment in Columbus Circle in February at the age of 39.
Trachtenberg made her acting debut as a child star with roles in Nickelodeon projects, including the television series The Adventure of Pete & Pete and the film Harriet the Spy.
The actress gained prominence first for her role as Dawn in Buffy the Vampire Slayer, which she played from 2000 to 2003.
She found further success as Georgina Sparks on Gossip Girl from 2008 to 2012. For her role, she was nominated as the choice TV villain at the Teen Choice Awards in 2012.