My first two guesses would be either worms or being egg bound. Egg bound hens don't always present with hard abdomens. Is she literally dragging her bottom on the ground, or did you mean that figuratively, as in she's lethargic?
No not actually dragging on the ground, just hanging low. I noticed her this am sitting in the run facing the corner. I thought perhaps she was going to lay an egg since I found one on the floor of the run yesterday.
Tonight I believe she was on the roost. No one on the floor where I had expected to find her. She is one of my older hens but not more than four. I will worm everyone tomorrow just to be on the safe side.