OKMULGEE, Okla. — Officials say doctors in rural eastern Oklahoma have declared a 16-year-old girl brain dead after her mother allegedly shot her in the head while she slept.

A spokesman for the Okmulgee County sheriff's office said Monday that Kloee Toliver will remain on life support until her organs can be donated.

Toliver's mother, Amy Hall, told officials that she shot Kloee in the head while she slept Thursday morning at their home about 35 miles (55 kilometers) southwest of Tulsa. Hall also shot and killed her 18-year-old son, Kayson Toliver, and tried to shoot her 14-year-old daughter.

Hall has been charged with one count of first-degree murder in her son's death. Officials say they will charge Hall with a second count of first-degree murder when Kloee is removed from life support.