Originally Posted by aforred
Sometimes you see this in horses that have been fed in a group situation. Since I have to guess, I would say they're used to being chased off their feed. I've got a couple right now that still do it after being here for two and a half years.
I'd agree with this. It sounds like nerves. I'm guessing she's the weakest link in the herd. She likely knows it and the mares were confirming it for her if she didn't.
Not sure what your routine is when she is at meal time but you might try standing guard for her when she eats and see if this makes a little difference after awhile. Don't do anything other than guard her and move around protectively, like your watching for any threats against her. You might even try talking to her like your actively protecting her, like you've got her back. That sometimes helps us humans get into the right body posture and energy.
And keep your back to her for the most part. You should be looking outward and around. Try it a few times and see if she responds at all.
Otherwise, yeah, get her off the crack pipe. LOL