I've recently had some issues with respiratory problems in my flock that I posted on here, but my CLs don't seem to be affected by it. And I haven't seen anything resembling mobility issues with any of my birds. Pip'd mentioned vitamin deficiency. What do you feed your flock? Is she way down on the pecking order where she might not be getting enough? I hope she makes it. It's tough to lose a bird, especially one so close to laying.
It's also a good possibility she ate something she shouldn't, especially since she is the only one affected. I had a turkey knock a box of fence staples on the ground, and when I came in the barn, the chickens were gathered around pecking at them. Luckily they were too big to fit in their mouths, but it wasn't for lack of trying. They also ate most of a piece of solid insulation that was blown out of the back of my truck. Surprisingly, there doesn't seem to be any effects from that.
