I'm confused!
All car insurance policies within the EU must have, as a very minimum, full third party cover. That means that if the policy holder is responsible for causing injury to others (or damage to their property) the insurer must meet any reasonable claims arising from such injury (or damage). Passengers within a car are just as much 'third parties', for the purposes of the insurance cover, as other motorists and pedestrians are. So I can't see how, if you caused an accident which injured your mother, any insurer could refuse to pay out on any valid claim from her against you. (It would be the equivalent of stating that they wouldn't pay out to an 80yo pedestrian that you knocked down on a zebra crossing. They simply can't make such rules).
Motor insurance policies don't normally provide any personal accident cover for the policy holder or for passengers when the policy holder is not at fault (although, of course, they can still claim against the insurance of a different driver if he caused an accident resulting in their injuries.)
So your reference to an exclusion by virtue of age has got me baffled!