The incident happened around 4:40 p.m. Wednesday on Church Rd. in the town of West Kewaunee.
Sherriff’s officials say the girl and her mother were bringing the horse in from pasture when the animal got startled. They say the horse took off and collided with the girl, who then was thrown against a tree.
The girl was airlifted to a Green Bay hospital. She is in serious but stable condition.
The name of the victim is not being released.