if those other vets said everything was ok, i'd be looking for another vet. They didn't find the rain rot that she had (which I would think would be something a vet would find first glance)
I also agree that she looks lame. I would stop lunging and jumping her.
I would call up vets and ask them to come out. Get the one that will come out the quickest.
I agree with FGR, x-rays are the way to go. They can be pricey, but for what they're worth, I rather have x-rays done than just guess what's going on under the skin.