Dec25th she was out with flock, in snow. All fine. Xmas eve husband found her under roost couldn't walk or stand. As of today I have her in house in cage. She eats, not much drinking. Clear eyes, runny poop, not discolored though. Alert, red comb, toes move, she shifts herself around, but can't stand. All 5 other hens fine. She couldn't have ate something bad as there is snow covering the ground and we use no chemicals. Also, none are laying presently, they molted right before days got short and I don't do additional lighting in winter. Any ideas?