The 3-year-old was only able to tell police officers what her car looked like and said “Daddy’s car drove away,” according to French media, which reported the incident on Sunday.
After driving more than 90 miles, the family heard on the radio a message from police asking them to pick up their daughter.
“They were obviously traumatized,” Thomas said, adding that the parents, who had “no previously reported problems,” were reunited with their daughter at a police station.
The family was heading south towards the coastal town of Saint Raphael, authorities said. They reportedly asked their other children, a boy and girl, if everything was okay, and no one noticed the toddler was missing.
Local police said they would talk to the prosecutor in Valence, the nearby town, to assess whether further action should be taken.