She is 6 years old, and it's mostly my own choice that she isn't ridden. I'm giving her 6 months without pads to figure out what to do with her legs and how to walk again, and also to rebuild trust with people on the ground.
The reason I upped the height a bit is simply because of her size. She just walks over a jump that low if she chooses to. She started herself over jumps, and it's helped that action that Walkers do with pads in their hind ends immensely. She used to move very mechanically, but now it's becoming a bit more natural and fluid. Vet checked her out and actually was surprised at how well she was doing, he said to keep them under 18" until he comes out again. He's an old guy, one of the official vets used in the Olympics when they came to Atlanta, and he said he had never seen a horse bounce back that quickly.
And you're exactly right about how contradictory they are to each other, that's why she surprised me that she wanted to do this. I'm having to hold her back, warm her up and cool her down, because if allowed she would just go over the little jump all day at a flat out canter. Again, I'm as surprised by this in her as anyone else is, I was expecting a lot of things from this mare and this was DEFINITELY not one of them! Not saying it wasn't a pleasant surprise though.
Her movement with pads was actually more like this guy: http://www.youtube.com/watch?v=s37NJC7dphA
without his lovely temperament (if you know him, you get the joke)
Thanks for your answer!
Edit: I will be putting a before and now pic up on her page in my "barn". There is already a before picture, but I will get her to stand still long enough and not eat the camera today. I hope.