Rose city archery has some inexpensive kid arrows that are rated to 30# and are about 28.5" long. I'll shoot them off my 30# samick with fast flight string so that might be pushing them a little. But they're cheap -- just $1-2 each.
A couple years ago, we took the kids to San Diego for Xmas. We all took takedowns. I took my 30# limbs, my wife took a 20# recurve & the kids took some easton 15# recurves. We stored them in the suitcase for baggage check. But a day or two before we left, I ordered some off amazon from Rose City & had them shipped to the condo we rented during our stay in SD. The next day, the arrows arrived & we all played around at the Balboa Park archery range. One dozen arrows for all 4 of us. When we were done, we left them at the range with a sign that said, "FREE TO GOOD HOME." The $15-20 we spent on arrows was less than the extra baggage fee if I took my own arrows and we didn't stress about losing them or breaking them while we were at the range. Shooting 60 yard field targets (or trying to) in the middle of SD from kid-weight bows is a kick. Nothing macho or serious -- just good ol' fun.
Warning, whenever we've ordered these for quick shipping, they seem to come in with all sorts of defects -- lose fletching, horrible nocks, nocks falling off, etc. But when I ordered them and waited a month for them to arrive, they all arrived in perfect condition. So, ideally, be patient & don't take whatever will ship in the next few days.