english speaking babysitter mother tongue

Hi, I'm looking for an english speaking babysitter mother tongue for mt kid of 4 years old, who should pick him up from school at 4pm and spend some time with him, sometimes together with his grandmother, till about 18:30, twice or three times/week. I need my son to become familiar with the language playing more than studying. It's going to be February, March and April. We live in de angeli area.