Leslie Carter died of a drug overdose on Tuesday, according to a police report filed Thursday.
Nicknamed "Ashton," Nick and Aaron Carter's 25-year-old sister was pronounced dead Tuesday evening in upstate New York.
Once an aspiring singer with the song "Like Wow" on the Shrek 2001 soundtrack, Leslie had a long history of mental illness and was on medication for depression, the police summary stated.
Her stepmother, Ginger Carter, called 911 on Tuesday from their Mayville, New York home, telling paramedics that Leslie (married mother to a 10-month-old daughter, Alyssa) was "asleep on her bed and not breathing."
Her father, Robert Carter, attempted CPR. Paramedics arrived and transported Leslie to Westfield Memorial Hospital, where she was pronounced dead at 4:59 p.m.
That morning, Leslie was feeling sick and appeared depressed, Ginger told police in a later interview. She later discovered that Leslie had fallen asleep in the shower, and escorted her to bed. That afternoon, Ginger and husband Robert discovered Leslie still unconscious in bed, and called 911.
Ginger appeared to be under the influence during the interview, according to the report, and told authorities that she had taken 5-6 pills for her depression -- possibly Xanax -- that day.
A full investigation into Leslie's death is ongoing, with a complete autopsy planned.
"I am with my family spending much-needed time together as we deal with this private matter," grieving sibling Aaron Carter (who canceled planned performances in Off-Broadway show Fantasticks) told Us Weekly in a Wednesday statement.
In addition to little Alyssa and husband Mike, Leslie is survived by four siblings.
According to a family source, her family was "completely blindsided" by her death. "She loved her family, she loved her baby," the source adds of Leslie, whose 1999 debut album was never released. "She was happy stepping away from the show business and just living happily with her family."