A New Jersey woman who was high on drugs in her car last year and left her 2-year-old daughter unattended for hours in her car seat, where she died, has pleaded guilty to manslaughter.

Deanna Joseph also pleaded guilty Monday to child endangerment and drug and weapons charges. The 39-year-old Alloway woman faces up to 15 years in prison when she's sentenced in March.

Joseph's daughter, Kayley Freeman, was found dead Aug. 26 in a car parked in the driveway of Joseph's home with the engine running. Joseph eventually admitted using drugs that day.

An autopsy determined Kayley died of positional asphyxia, a condition in which a person's breathing is obstructed because of the way his or her body is positioned.