The Billings Gazette reports 34-year-old Elvira Najar was arrested early Thursday and appeared in Justice Court on a charge of assault with a weapon. Her bail was set at $7,500.
Court records say the boy told police he had been in a car with one of his friends and his mother, who was upset because she thought he was spending time with his father.
The boy said he got out of the car and his mother drove up onto a curb and hit him, knocking him down.
The boy's friend said Najar told her son: "I brought (you) into the world ... I can take you out, and I don't care if I go to jail for it."