Whoa that does seem like neurological issues. I’ve never seen that.Ground layer looks better than I've ever seen her. Her new feathers are growing in quickly and thoroughly. She dug a dust bath for herself, knows where her food and water are, and manages to find (eventually) the tomatoes I toss for her.
I have seen one concerning behavior though, and not just one time, but up to a couple times per day. As she's pecking around in the grass (which is very short outside the duck house), she will suddenly run backwards 8-12 feet while whipping her head back and forth in the air. It's how I imagine she'd react if someone surprised her by grabbing at her head. After she snaps out of it, she seems fine again, but none of our other chickens do this.
Any ideas? It seems almost neurological.