A room in exchange for English with kids

Hello! My name is Myriam, mother of 3 kids (aged 8, 5, 3).
We are looking for an aupair to live with us in Madrid. Take care of the kids 3 or 4 afternoons during the week and spend a couple of weekends per month with us. Or maybe if you want just spend a couple of nights during the week and 2 weekends per month. We can be flexible. We just want our kids to have an english speaker around. You need to be active and playful :)