Melissa Renee Medema, 27, was arrested on Wednesday on charges of endangering the welfare of a child.
Springdale Police say footage shows her abusing a 1-year-old child who was in her care.
Medema was taken to the Benton County Jail.
The child's mother says she installed the camera after becoming suspicious of Medema's treatment of the toddler.
She said the video shows her shaking the child, who had to receive medical treatment for her injuries.