Would they be interested in living somewhere other than London/major city? Or is it not really worth trying and I should just look for other options?
We live in the relative countryside, a village a short bus ride outside of a large town which is in easy distance to many places by train (Birmingham, Chester, Manchester, Aberystwyth within an hour, Liverpool, Leeds, Cardiff within 2). The town has a nightclub and lots of nice bars/pubs/cafes, lots of schools/colleges as well as a university centre. I think it's an OK place to be a young adult, but I don't think I'd choose here if I was an au pair. Don't know if anyone has had any different experiences, though.
I au paired myself at 18 (I started at 17, actually which I'm sure is illegal) and refused to go anywhere other than a major city but I was a bit of an arse.