If I were starting over on kids' headphones, I'd go straight to the Puro BT2200

Kids’ headphones are one of those categories where you can spend anywhere from fifteen bucks to a hundred, and the cheap ones are genuinely terrible — tinny sound, uncomfortable after twenty minutes, and they break the moment a child looks at them wrong. The Puro BT2200 costs more than the junk, but it has actual volume limiting that works, real over-ear padding that survives a three-hour road trip, and sound quality that doesn’t make you wince. If I were starting from zero again, I’d skip the trial-and-error and just buy these first. They’re the pair you eventually end up with anyway.