Daisy is a 1-year-old RIR. Very healthy and normal until a month ago when she started laying only whites and yolks in the nestbox, no membrane or shell. Sometimes she seemed quiet and uncomfortable as well. But she'd always feel better later in the day. I began giving oyster shell to the girls in addition to their layer pellets, but that didn't help. So every morning for the past week, I've been feeding Daisy a tablespoon of cottage cheese with about a half of an eggshell crushed and mixed in. She devoured it, and began laying eggs with shells again. But this morning, I watched her expel a yolk and white while pooping. She stood quietly most of the day with her tail down and head tucked in. I'm afraid I'm losing her. Any advice, Please?