I made WONDERFUL progress with Bella today. She had let me pet her and stuff, but never like this. I used an actual brush and got her mane mostly under control, then braided the part that I'd just untangled so it will hopefully flatten out and get out of the habit of tangling. I still have the big, bad tangle left to go. If brushing a mane sounds simple, think about the pulling, the big movements with both hands, the fact that the human's body is pointed directly at the horse. She was relaxed about it by the time I got done. Licking and chewing. Not quite napping, but pretty okay with it all.
And I petted her all over! Well, not all over. Before all I could rub was her shoulder and if she felt good her neck. Today I rubbed all around under her halter except the nose and poll, and even reached under and rubbed on her left side. I tried to straighten the halter since it's a little cockeyed, but she blew up and left me. Got back to rubbing and brushing, and worked my way back to her tail, down almost to her hock, to her knee in front, and over onto the left side of her back and neck. Wow. Not much belly rubbing, she would shift her weight when I rubbed her cinch area, and I'd work my way back up to comfortable territory, back down to cinch area, back up, so that she never had time to get totally alarmed about it, but I did get to rub there a bit. No udder rubbing just yet, I'd like to keep myself in one piece!
Next time I go out I may not be able to touch her... She's an enigma. I hope we've made some sort of breakthrough, but my gut is telling me we'll probably go back a few steps, then forward again. That's okay. It's such a rush when things go well.