Now it's emerged that the mother and daughter missed the public memorial to attended a private family service for the late Glee production assistant.
According to unconfirmed reports in the US, 45-year-old Julia and her mother Betty Lou Motes joined other close family members at a funeral, where they brought pictures of Nancy to remember the 37-year-old.
Meanwhile, Saturday's public service was attended by friends including Glee star Jane Lynch and other co-workers of Nancy, who was a production assistant on the musical show.
"The family didn't want the focus to be on them, they wanted it to be on Nancy and her memory," a source told In Touch magazine.
"It was tough for them, but I think Nancy would've been happy with the way it was done."
Julia and Nancy had the same mother, but different fathers; Julia is the daughter of the late Walter Grady Roberts, and Nancy's father is Michael Motes.
The two sisters had a complex relationship; they were very close growing up but in the days leading up to her death, Nancy spoke out against Julia in a series of angry tweets.
The production assistant was said to be battling an addiction to prescription drugs. She took her own life in February, dying of an overdose.
According to her fiancé, Nancy struggled with Julia's fame, and was upset by the actress' departure from the family home for Hollywood when her sister was nine.
"Nancy was proud of Julia but she had severe abandonment issues,' said John Dilbeck, who was engaged to Nancy.
"She had a knee operation as a teen and piled on weight because she couldn’t exercise. While her sister was the Pretty Woman, Nancy was an overweight, insecure teenager."