External Au-pair

I am looking for a native English speaking living near my neighborhood (Conde de Casal, Madrid) to pickup my kids (ages 9,7, and 4) from the school, having lunch with them and leave them back at school (school is 5 minute walking from home). 
The working hours will be three days por week from 12:40 to 15.00 starting from September/October.
Thanks!