It was an incredible sight yesterday to see her lying down in a deep sleep. While she had been eating & drinking well, she was pretty unsure about me, wouldn't come up & eat her feed while I was around, & tended to hold her breath & clench her jaw. I started slow, working on some Approach & Retreat the past couple of days.
Yesterday's session saw quite a bit of progress. Instead of going straight to the round pen, I opted to start with some positive reinforcement training so that she starts to look forward to being worked with & we can build her confidence. I know you mentioned a situation where round penning at a friend's place didn't go very well. Because she was so unsure of things, I started by approaching, getting a touch on her neck or nose, clicking, dropping some pellets into a pan on the ground, & retreating. Thankfully, she was interested enough that she would eat out of the pan & eventually, while I was holding the pan. As we continued, she began to lick & chew, take deep breaths, look as if she could take a nap, & cock a hind foot (as pictured). From there, I haltered her & spent a bit of time rubbing & brushing on her. She eventually figured out that it was safe to eat out of my hand. The light bulb really went off for her then. After unhaltering, she continued to follow & eat from my hand.
 This morning, she was much more confident. She met me at the gate at morning feeding time & had no issue with me reaching through the fence to rub on her. During our session, she was much more sure of me. We haltered much quicker, did some desensitizing to the lead rope, & worked with her front feet as they desperately need to be trimmed. We'll continue to build that confidence from her pen with positive reinforcement & some simple groundwork exercises before we move out to the round pen & repeat. I'll be working to instill new habits, confidence, & curiosity over the not-so-great experiences she's had in the past. The time will come to teach her how to respond to pressure, but she could quickly shut down if I were to jump into that right away.