AU PAIR JULY AND AUGUST AND REST OF THE YEAR IF SHE LIKES

Hello 
I am looking for an British Native girl au pair, from London or Surroundings.
She will live at home taking care our kids.
7 years, 5 and 4 years old.
For July and August full time, In September only for the afternoons.
We will pay per weeks.
We need somebody with responsibility, who likes kids and play with them, tell stories and be with them.
We live in Madrid city near the center and malls.