I’m doing the same thing right now, except my hat is an adult size (I think) and I have 80 stitches between 3 needles! After having to restart so many times because my ribbed rows expanded so much that I couldn’t keep them all on the needles, I created three crocheted things to keep the stitches in place (I’ve been crocheting for 10 years (and I’m 16) but knitting only for a few months).
Basically, with a strand of contrasting yarn, tie one end to the needle to where it is snug, but can come off. Then about 4 inches later tie it onto the needle again. This will keep the stitches on easily. To get it on or off, just put one end on, scrunch up your work on the needle, and slip the other end on. Then work it towards the center of the needle so that it can’t slip off.
The tension of the yarn will prevent the row from growing off the the needle. I made three of them, and then tied another scrap of bright yarn around the one that has the beginning of my round so that I can count rounds and make it easier on myself.
I hope this helps.