Native English speaker needed: Chamartín - Madrid

We are looking for a native English young person, energetic and imaginative, to play and speak with our children two days a week (Tuesday and Thursday from 17:30 to 19:30). They are 7 and 4 years old. We live close to Chamartin station and Plaza de Castilla (five minutes walk).  We need someone who stays in Madrid at least until June 2015. 
Salary: Eur 150 per month.
If you are interested , please, send mail at edalumbre@gmail.com