speak eanglish with kids

We want an english speaker student to speak with our children (13, 11 and 6 years old) two hours on tuesday and thursday afternoons. We live between Santa Cruz and Circular squares, close to the Valladolid University. We dont' need a  teacher, just an university student who likes to read or play with the little one and to speak and perhaps revise some english homework whith the older ones.