EXTERNAL AU-PAIR WANTED

I am looking for an English speaking external Au-pair to help look after my two little girls, aged 3 and 6.
The work hours would be approximately 4.15 to 8.00, Monday to Thursday, from now until the end of the school year.
The job would consist in picking them up at school and playing with them, taking them to the park or to their extracurricular activities, watching a movie, etc. 
Overall spending time with the girls in English. They already both speak in English as I speak to them in English. 
There is no housework involved. We live in central Madrid, near Santiago Bernabeu.

Salary: Eur350 per month.