E.M.
Well, hand flapping is a red flag for autism which may be why people are saying something. BUT not all autistic kids flap their hands and not all kids who flap their hands have autism. My daughter kind of flaps her hands when she gets really upset--she also has super strong emotions--happy, sad, mad, excited--you name it. She is not autistic (she does have ADHD--and I have never heard that hand flapping is related to ADHD so no worries). When my daughter gets excited she gets really giddy and silly and makes funny noises and sticks out her tongue too. Maybe you could just ask people directly why they think it is a big deal? Then you could just say "yes, she gets very silly when she gets excited but it's nothing to worry about."