California has very broad law under Penal Code Section 272 Contributing to the Delinquency of a Minor and Penal Code Section 273a, Endangering Health of Child. The question does not indicate whether the driving is taking place on a highway, so we don't know if a license is required or not. If the driving is on a highway requiring a license, there is violation of the vehcile code which could bring the conduct under the provisions of Contibuting to Delinquency. Absent some other indication of of danger or irresponsibility, there could be a qustion as to whether the conduct arrises to Child Endangerment.
It could be. It may depend on the circumstances. You can contact the local child protective services and ask them.