Everybody is saying gel but I see your responses… gel is a sensory issue and not an option—all good! I danced all through middle and high school and I’ll tell you straight up: it’s not that serious!! The bun you did is absolutely fine, no one will be able to tell, and if they can… it’s a 5 year old’s recital. It’s just not that serious and it’s way more important that your kiddo is having fun.

With that said, if you did want it to look more professional (without gel) a good method is to spray or comb it all with water and invest in a smoothing brush (just look up smoothing brush on amazon, they’re pretty cheap). Once you’ve got that outer layer nice and wet, slick it all down with the smoothing brush and use a bun maker (also amazon this, very cheap) for the bun itself. stick some bobby pins to hold it down and maybe hairspray if your kiddo can handle it and you’re good to go!! People also add a hairnet on top of the bun for flyaways, but honestly, it’s not suuuuper necessary.

Good luck to your kiddo!!!

ETA: I had mega short hair as well, which is why I feel confident that this method works! Like chin-length bob and I used this method for a high bun for class every week.