KERRVILLE, Texas – A 20-year-old woman who left her two kids in a hot car for 15 hours, ultimately killing them, has pleaded guilty to all charges in connection with the fatal incident.

Amanda Hawkins has remained behind bars since she was charged in the June 2017 deaths of her daughters Brynn Hawkins, 1, and Addyson Overgard-Eddy, 2.

According to Hill Country Breaking News, Hawkins will be sentenced by a judge Dec. 12 on two counts of abandoning or endangering a child and two counts of injury to a child.

Kerr County Sheriff Rusty Hierholzer previously told KSAT Hawkins left her two daughters in the car while she was at a friend's house.

Hierholzer said she tried to bathe her unconscious kids before a friend prompted her to take the girls to Peterson Regional Medical Center in Kerrville.

At first, Hawkins claimed the girls were at Flat Rock Park smelling flowers when they both collapsed. Investigators, however, concluded that the children were intentionally left in a vehicle overnight on June 6, 2017, until noon on June 7, 2017.

Authorities said she didn't immediately take the children to the hospital because she "did not want to get into trouble."

Another person, 18-year-old Kevin Franke, is charged with two counts of abandoning or endangering a child, two counts of injury to a child, two counts of manslaughter and two counts of murder relating to the girls' deaths.

Franke remains behind bars on those eight counts, online court records show.