The accident took place on private property, so there would be no prosecution, police said.
The girl's mother - 39-year-old Tina Rowe - was teaching her how to parallel park at about 3:30 p.m. Saturday when the girl backed the car over her, police said.
Police believe the girl may have hit the gas pedal instead of the brake.
Rowe was pinned under the 1997 Chevy Cavalier. Emergency crews arrived to get the car off her, but Rowe was pronounced dead at the scene.