ADEL, Iowa -- The adoptive grandmother of a central Iowa teenager who starved to death has been sentenced to 20 years in prison after admitting she didn't seek medical attention for the dying girl.

Sixty-three-year-old Carla Bousman, of Perry, was sentenced Friday after pleading guilty to neglect of a dependent person and six other charges in the May 2017 death of 16-year-old Sabrina Ray. Authorities say Sabrina weighed 56 pounds and was severely malnourished when she died.

Sabrina's adoptive parents, Marc Alan Ray and Misty Jo Bousman-Ray, face several felony charges in Sabrina's abuse and death, including first-degree murder. They have pleaded not guilty.

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Bousman was reportedly the caretaker of Sabrina Ray and her siblings on May 12, 2017, the day she was found dead. The Des Moines Register reports Bousman admitted she found her granddaughter vomiting and found the girl had soiled herself. She said she thought the girl wasn't feeling well and cleaned her up.

Bousman admitted in court: "When I recognized she was in distress, I did not call for medical assistance or take her to a doctor," according to the station.

During sentencing, Bousman was emotional, reports CBS affiliate KCCI.

"I can't change what is done now, but I'm very sorry. And I miss all my grandchildren all very much," Bousman said.

When the judge asked, "How could you do that to your grandchildren?" Bousman said she felt manipulated by her daughter and son-in-law.

The Des Moines Register reports Bousman also admitted that she locked Sabrina's two sisters in a room with the girl as she was dying. She also admitted concealing evidence after Sabrina died.

In February, Sabrina's adoptive brother Justin pleaded guilty to willful injury. He is accused of "drop-kicking" the girl down stairs.

