A North Carolina woman is pleading guilty to killing her 15-month-old niece in a case in which social workers are accused of ignoring, then covering up the child's abuse until after her death.

Thirty-nine-year-old Ladybird Powell pleaded guilty Monday to involuntary manslaughter. She faces 12 years in prison.

Powell was arrested in January 2012 — one year after Aubrey Littlejohn's death.

She was taking care of Aubrey while the toddler's mother was in jail awaiting trial in a marijuana-trafficking case.

The plea is the latest development in a case that sparked anger in the Native American community.

Aubrey was a member of the Eastern Band of Cherokee Indians, some of whom say the Swain County Department of Social Services didn't do enough to protect Aubrey and other Native American children.