Heck yea, Holly was a real bad bucker for the first few days in the round pen under saddle. It's just a matter of getting used to stuff on her back and hanging stuff all over here. I stuffed a pillow case with a wide assortment of junk and tied it on and let it move about! And plenty of stuff that would cling and clang and shift around a lot in the pillow case on her back. The more junk you can find to load up on there that moves around in the sack, the better it is. That simulates a child who won't sit still and gets them used to weight leaning back and forth and from side to side. I tied more junk to those leather straps behind the saddle seat too. Figure that lots of tiny kids will "knee" the horse and crawl around on top the saddle before they actually sit down, so I prepare the horse for that such stuff in training.
Now if you really want to add some serious reining stuff on a mini like I put on Holly so a kid can ride by "themselves"and my other ponies, this is what I did for that:
Bear with me, this is hard to explain, but first of course this is done after you have done your ground driving and your horse reponds to direct reining etc. This is how you get a jam up finished pony: How to teach them to rein and yield to leg pressure like a kid would ride if taught right:
Ok you put the horse between your legs like you are riding. And you assume the position of a rider, but of course you don't sit down on the horse. And you pick up the reins right there and work them like that. Now, you are moving your legs and feet around, in baby steps keeping contact with your horse's sides and bumping her sides with your knees, calves, and turning and turning and manipulating them from side to side, which ever direction you want to be turning. It's hard doing this on a larger pony without loosing your balance and accidently plopping down in the saddle every now and then, but so simple with a little mini, but you have to keep one leg off and one leg on them to push them over just like you would do if you were mounted. About where a small child would be kicking them in the sides etc. You just keep pushing them around, one side and then teach the other side. Man, you can get one heck of a 360 on a pony like that too. Like I said, my ponies could do anything my big horses could do.It's really a lot of fun.
Now if you think about it: you are "towering" over these little horses and ponies, where are they going to go, and what are they going to do, and they know it, and they are not about to want to rear either because they know you got them and can clunk them real quickly if they do, but I think that's why I never had a pony rear on a kid and got a lot of them broke to death for kids like that and off they go on their merry way. Still wish I had a small enough kid though!
I got some pictures here somewhere I'll post as soon as I find them of Holly being trained like I am describing