yeah it looks like it is more likely to be the engine size not her age as regardless of age she is still a new/inexperienced driver. Various underwriters have different rules eg many that we use will not cover you on a GTI unless you are a certain age/held a licence for so long etc.
That said
some insurers may look at the length of time she has held her provisional due to her age e.g if she has held it 25 years for example, why has she not yet passed? has she failed loads of tests (and as such is she a higher risk?)
Martin
