English mother tongue part time babysitter in Milan

Hi,
we are an italian family living in Milan and we're looking for an english mother tongue babysitter for our two children (Emma 8, and Luca 5) for taking them back home from school, from three up to five times a week (negotiable) at around 4PM and look after them for about 3 hours, occasionally taking them to activities but mainly having english conversation and playing with them.
We live in a central position, very convenient as it's only 5 minutes walk from three different underground stations.
This is a part-time (9 to 15 hours per week, negotiable), live-out position, the job can start any time from now and last as long as possible; preference will be given to british english mother tongue candidates already living in Italy.