Ah, HFMD is really tough on the little ones, especially with the mouth sores keeping them up at night. My friend's kid had it last year and she found that cool foods like ice cream, yoghurt and smoothies helped ease the pain a bit, plus she gave paracetamol before bedtime so her son could sleep better. I'd definitely check in with your PD to see if there's anything else they can suggest for faster healing or if there's a mouth gel that might help with the sores. The good news is most kids bounce back within a week or so, so hang in there.