Upon further review and in much better light, I see that what I thought was a very small amount of blood on the white cresting was actually some clay-ey dirt with plenty of matching dirt on the vane. I went back out and there was definitely no blood anywhere around. The only reason I thought I hit her at all was that she was limping a little. She could have been limping before I ever saw her, because I was looking the other way when she appeared in my opening.
I have accidentally shot arrows with the rest in the down position in practice and they usually hit a foot to a foot and a half low depending on distance. My suspicion is that I hit the hoof on the far leg, giving no blood but maybe making her limp. I could also have hit a rock that popped up and hit her in the leg. I still can't figure how the arrow snapped. The front blade of the Snyper was curled up letting me know it hit something hard like a rock or possibly her hoof as it was planted on the ground. It is all speculation now, but I am certain that I didn't draw blood, which makes me feel better. I'm still upset over blowing the shot.

The most important bloodtrail leads right to the foot of the cross