Good to hear from you, Marji. I am so sorry to hear of your nephew's illness - how scary for your brother, SIL and the entire family.
I would say DEFINITELY a monster. I like the family of monsters - something like that and you need to make a booboo on the monsters head, don't you think? Monsters these days are so "in" and so popular. My kids love stuff like that, even now. If you make a second monster, maybe it's a (cute, harmless) doctor monster and it hugs the booboo monster? This could be very therapeutic for him.
Anyway, that's what popped up to me. Good luck, and all the best to the little one and family!