Failing to disclose who the driver is - isn't that obstructing justice?
Also, as the registered keeper, are you not responsible for any fines, penalties incurred?
We need judges to man up & start handing out fines - in the woman's case, a hefty fine for obstruction would soon help her memory.
Also, what about making sure the car was covered by insurance at the time of the offence? If insurance is only for her - then surely no-one else should be driving - unless third party on Doc, in which case, she must declare who it was so their insurance can be checked out...