Police in Yangjiang in the southern province of Guangdong said in a statement that a 29-year-old woman surnamed Chen was being investigated after the video went viral.
She lives with the girl's grandfather, a 50-year-old widower surnamed Ye. Chen told police that she started the scooter to scare the girl, who didn't want to leave home with the rest of the family.
She said that she accidentally ran over the girl's legs, but later checked and found that the girl wasn't seriously injured. The police statement said the girl suffered leg injuries.