Native English speaker to play with 6-8 years old kids (2 h per week)

We are looking for an active English speaking person, who loves kids and enjoys playing with them. Once a week, from 18.00 to 20.00 pm. I have a boy, 8 years old, and a girl, 6 years old. They already speak English, but I want them to use when playing at home to practice. I don't want English classes, but someone that talks to them and makes them talk.

We live nearby Chamartin train station (3 min. walking). Metro: Bambu, Duque de Pastrana or Chamartin.