PeteB - You're probably right in that it won't affect the insurance. However, if she only has a provision licence, then that it NOT valid in UK, therefore she is driving without a licence. Most policies only cover the driver if s/he holds a licence to drive, or having held such a licence is not disqualified from holding etc etc.
In this case, the P/L is not valid in UK, therefore she has no licence. Given that she would be driving with consent of policyholder, the insurer will have to deal with any TP claim, but would have right of recovery under the policy against Policyholder and driver ???????????