One of my girls was laying perfect eggs for about 2 months before her sister hatched some chicks, suddenly they then started having calcium deposits on top and sides. Every now and then they're also extremely thin to the point that i could almost put a finger through just picking it up, but it STILL has calcium deposits on the egg! I offer oyster shell separately to their normal feed so they can pick at it when they need to. Any thoughts on what I should do to help my girl out? All my other hens are laying fine.