Hello. I have a Bantam Cochin girl who has laid 2 eggs so far. The first was fine. The second was smashed in the coop and the shell was very pliable. All of the chickens have plenty of oyster shell available. For feed, they also get: layer pellets, a 4-grain "treat" and all of the scraps and greenery from my garden and compost. What's the problem and how do I strengthen her eggs?