Afternoon Sitter

My 9-year-old son is on the Autism Spectrum and will attend summer school from 8-12. I'm looking to cover the hours from pick-up at noon until later in the afternoon. He has expressive and receptive language disorder as part of his Autism, so communication is a challenge for him. He uses lots of scripts but with familiarity is pretty easy to understand. He will need to have lunch and do one or two household jobs, other than that the day is open for hanging out or activities. My 12-year-old daughter will be in day camp for some of the weeks, but sometimes will be around. She is very self-sufficient, so she doesn't really need coverage.