Mother locks 7 yo in Trunk

CNN:

A mother who left her 7-year-old son locked in the trunk of a car while she partied in a bar has pleaded guilty to child abuse and false imprisonment. ... Powell was arrested during her birthday celebration on August 23 at a bar in San Diego's Ocean Beach neighborhood. A witness had alerted police that the boy was in the trunk of Powell's Volvo, which was parked outside. The boy was found in the trunk with a pillow and a sleeping bag. Police said Powell told them she put the boy in the trunk for safekeeping when she was unable to find a babysitter.

Now I agree that this is irresponsible and a bad judgement, but child abuse and false imprisonment seems a little extreme to me. Is sending a kid to his room false imprisonment?