Your only real possibility of finding a european nanny here is if there is a daughter of one of the families who live out here who is finished school and looking for work. Not sure how easy it would be to find someone though. I think the only real option of finding a western au pair/nanny here is to go through an agency in the UK or in europe and sponsor someone to come out - but then you would have to bear in mind that you would be paying a european/british equivalent salary.
I am working as a governess here and came out through my british agency and the only western nannies I know here all came through UK agencies too. Good luck!