A Tulalip woman who left her two young daughters in a filthy car while she used drugs has pleaded guilty to second-degree murder in the death of one child and criminal mistreatment for neglect of the other girl.

The U.S. attorney's office is recommending a prison sentence of 8 to 13 years for 38-year-old Tulalip Tribes member Christina D. Carlson when she is sentenced July 21 in Seattle.

Carlson pleaded guilty Tuesday in a plea agreement with federal prosecutors for the October 2012 death of her 19-month-old daughter and neglect of the other girl who was nearly 3 years old. They were covered in human waste when emergency responders found the car parked on the Tulalip reservation.

Carlson said she left them alone to buy drugs for herself.