Hi thisismyname,
Yes, I treat several ME sufferers and all have made significant progress with increased energy levels and clearer minds.
Ususally best to start with shorter sessions (especially as your son is only 7) and incorporate immune system and elimination channel areas as a priority. ie. lungs, urinary tract, lymphatics, liver, colon etc.
In my experience children love having reflexology and it is a lovely way to spend time with your son whilst helping him