In most states your mother would be able to place a claim against the at-fault person's insurance policy for the damage her car sustained even though her car was not insured at the time of the accident.

Normally you can contact the at-fault party's insurance company and place a claim against their property damage liability coverages for your damages. It does not sound as if the police responded to this parking lot accident but if they had and cited your mother for being uninsured then she would need to take care of that ticket and any penalties associated with it.