Check your insurance coverage

Traffic law is one of the areas covered by criminal law. Unless the driver was recklessly driving, most states will only punish a driver for his own negligence or that of a family member. As I said, traffic law is criminal law so why should a state punish a driver simply lending her car to another and she herself does not have the mens rea? From social point of view, imposing a strict liability like this would discourage people lend ANYTHING to other people. What if your friend borrowed a knife from you and committed suicide, will you be committed manslaughter because you were aiding the suicide? Does it make sense?

There are a growing number of states would hold dirver liable if the driver who she lends the car to has an accident. To date, this is still a minority rule. Normally an insurance coverage would specify if they do that. So, check it.