Michelle Trachtenberg—the film and television actor known for roles in Buffy The Vampire Slayer, Gossip Girl, Harriet The Spy, and Ice Princess—had died. Her death was confirmed by ABC News. The outlet reports that she had undergone a liver transplant recently and is believed to have died from natural causes. She was 39.

Louise Fitzhugh’s 1964 children’s novel Harriet the Spy was brought to life in a 1996 movie of the same name. Harriet (Michelle Trachtenberg) is a precocious sixth-grader who’s destined to be a super-sleuth.

From "Gossip Girl" to "The Ice Princess" and "Buffy the Vampire Slayer," here's a look at Michelle Trachtenberg's career in photos.