One of my BO hens, Lilly, has for a while been walking kind of funny. All the other hens bend over and peck the ground with their fuzzy butts in the air. Lilly looks like she is in a "squat" posture, with her tail down. When she walks it is more upright than the others. I have to lift her on to a roost every night - it's only about a foot and a half high, because she can't get up there herself. She lays an egg on the ground almost every day and eats and drinks and poops just fine. I haven't seen the rooster at her lately, but he used to romance her quite a bit. She used to roost on top of the nest boxes, but I blocked those off, because my birds are all pretty big and I didn't want them jumping that far any more. She started having these troubles a couple of months ago. Any thoughts?