@TinaRew your videos of your hen walking show her pausing and backing up incrementally. This is normal chicken behavior when scanning the ground for signs of food. I see nothing that suggests to me that your hen has a neurological issue.
When my rooster was walking backwards, he dragged his beak on the ground, unable to raise his head. He appeared helpless to snap out of it when it happened. It incapacitated him. It was extremely obvious he was having trouble moving normally. Within an hour of giving him a vitamin E capsule, he stopped doing it and returned to normal behavior.
But do keep an eye on your hen. If her behavior becomes such that she doesn't seem to be able to do what she is needing to do and seems frustrated and confused, then she may be having symptoms of torticolis.