The cause of death for actress Michelle Trachtenberg, who died in February, was confirmed to be complications of diabetes mellitus, a spokesperson for the New York City Office of the Medical Examiner confirmed to CNN on Wednesday.

Her cause of death was initially ruled as undetermined because her family declined an autopsy, a spokesperson for the medical examiner’s office told CNN at the time, and because Trachtenberg’s death was not deemed suspicious by law enforcement, the medical examiner’s office honoured that request, the spokesperson said.

Trachtenberg, who was best known for appearing in “Harriet the Spy,” “Buffy the Vampire Slayer” and “Gossip Girl,” died on February 26 in Manhattan. She was 39.

Police responded to a 911 call just after 8 am local time and found a woman unconscious and unresponsive inside a Manhattan apartment.

She was later identified as Trachtenberg, an NYPD spokesperson told CNN at the time.

EMS responded to the location and pronounced the victim deceased.

An NYPD source told CNN that Trachtenberg reportedly had a recent medical issue and that her death appeared to be related to natural causes.

Her manner of death was ruled as natural, the spokesperson for the medical examiner’s office told CNN on Wednesday.

Trachtenberg started as a child actor on Nickelodeon in the ’90s where she first gained attention with a role on “The Adventures of Pete & Pete.”

She went on to star in Nickelodeon’s first feature film, 1996’s “Harriet the Spy,” sharing the screen with Rosie O’Donnell.

In 2000, Trachtenberg appeared in the WB hit series “Buffy the Vampire Slayer,” playing Dawn Summers, Buffy’s (Sarah Michelle Gellar) younger sister.

She went on to star in a variety of roles including the raunchy teen comedy “EuroTrip,” premium cable drama “Six Feet Under” and the Disney movie “Ice Princess” before playing the villainous Georgina Sparks on “Gossip Girl.”