"It is with deep sadness that the family of Nancy Motes … confirms that she was found dead in Los Angeles yesterday of an apparent drug overdose," the statement reads. "There is no official report from the Coroner's office yet. The family is both shocked and devastated."
No further information is available at this time.
Motes, 37, was the younger half-sibling of Julia, her brother Eric Roberts (father of Emma Roberts), and their sister Lisa Roberts Gillan. They shared the same mother, Betty Lou. Motes's father was Michael Motes.
She reportedly worked as a production assistant on the popular Fox show "Glee," a job that Julia helped her get.
Julia skipped the Oscar nominees luncheon on Monday where she was being honored for her Best Supporting Actress nomination this year in "August: Osage County." There's been no word so far from Eric or Emma on social media.
In an August 2013 profile in the New York Daily NewsNew York Daily News, Motes - who once weighed close to 300 pounds before gastric bypass surgery - detailed the rocky relationship she had with her sister for the first time.
"When I was in high school and she was an adult, she would just let me know that I was definitely overweight,” Motes, 37, said.
“She would make it quite clear to me and in a not-so-nice a manner.”
Motes also said that when she made her dreams of Hollywood known to her A-list sister, she "did not want to see me go down that path".
"Mostly because I was overweight. My weight has fluctuated my entire life. So I just got a lot of criticism from Julia, which was very discouraging for me," she said.
At the time of the Daily News's interviews, Motes was living in an apartment in Malibu with her fiancé, John Dilbeck, who worked as a film and TV locations manager.
The paper reported that they had plans to marry in May of this year.
Jenny Depper writes for Yahoo Celebrity