Unfortunately, in UK law, the driver of a vehicle is always liable in an incident involving a pedestrian, even when it isn't your fault. I can't advise whether the amount you're are paying is reasonable or not, that would be like trying to advise whether your shopping bill was too much without knowing everything you bought. Any claim will be on your daughters records for six years, but should only be taken into consideration for three. Your granddaughter does have the right to claim for the increase in premium from the pedestrian for the loss she has incurred as a result of his negligence if the incident was his fault. Though I'm completely against the actions the insurer are taking, they will see your granddaughter as being an additional risk having been involved in an incident. What she should do is complain to the insurer and the financial ombudsman service.