If you don’t have to return what the neighbor gave you, I’d go to your local dry cleaner and have it tailored or just let him look a little off for free.

The shorts are usual just plain black shorts which you can get in youth sizes.

Shirts can be bought on Amazon in youth large.

My son needs to get a referee kit. The issue is that he is 5'5" and 97 lbs. Our neighbor gave him a kit with the clothing in women's size S, and although the length was fine, he was swimming in it width-wise. I don't imagine they make them in kids' sizes, so what have other people with skinny kids done?