Dawn Summers on 'Buffy the Vampire Slayer' was magical energy turned human. Michelle Trachtenberg made her everyone's kid sister.

Soon after, she starred in popular Nickelodeon film Harriet The Spy, which followed the adventures of a sixth grader who aspired toward espionage. Trachtenberg led the film when she was just 11 years old.

Actress Michelle Trachtenberg, known for roles in "Buffy," "Harriet the Spy" and "Gossip Girl" was found dead in New York City Wednesday at age 39.

In a statement provided to Entertainment Weekly on Wednesday, O'Donnell said of Trachtenberg, "I loved her very much. She struggled the last few years. I wish I could have helped.

Michelle Trachtenberg, the actress best known for her roles as Dawn Summers on Buffy the Vampire Slayer and Georgina Sparks on Gossip Girl, has died. She was 39. Trachtenberg was found unresponsive in her New York City apartment early Wednesday morning,

Actress Michelle Trachtenberg, known for her roles in "Harriet the Spy" and "Gossip Girl," has died. She was 39.

Michelle Trachtenberg, an actress who starred in “Gossip Girl” and “Harriet the Spy,” was found dead in her luxury Midtown Manhattan apartment early Wednesday, police sources said. Trachtenberg, 39, was found unresponsive by her mother in her apartment near Columbus Circle at 8 a.m.

Trachtenberg starred in a variety of kid-oriented movies and shows, making her film debut in 1996’s “Harriet the Spy.”

Actor Michelle Trachtenberg, who attained fame by playing innocent teenagers in series like Buffy the Vampire Slayer and Gossip Girl, passed away at 39. Reports say she was found unresponsive in her residence in New York City.

Fans mourning the loss of Michelle Trachtenberg following her death Wednesday at the age of 39 are revisiting some of her most beloved works, among them, Harriet the Spy. Before the actress became known as Dawn Summers on Buffy the Vampire Slayer and Georgina Sparks on Gossip Girl,

Michelle Trachtenberg, the actor known for “Gossip Girl,” “Buffy the Vampire Slayer” and “Harriet the Spy” died Wednesday. She was 39.

Michelle Trachtenberg, an actor best known for her roles in "Buffy the Vampire Slayer" and "Harriet the Spy" has died at age 39.