Our oldest girls started laying 2 weeks ago, 9 girls 22 weeks old we are getting two and once three a day, they skip a day a week so far. The shells all seemed to be very hard. They get Kent Multi flock and have a pail full of oyster shell. Well today along with a tiny first egg from one there was in the nest box next to it our first shell less egg At 1st I thought it was another broken egg but there was no shell at all and like a white rubbery part under it. One hen who must of laid that shell less egg has some yolk on her butt. I put a hand full os oyster shell next to her on the roost hoping she'll figure out to eat that to help her eggs. Any tips? Can this be just because she is a new layer or is it for sure a calcium deficiency? Also I know when they start laying the eggs are smaller... how long till they are the chickens full size eggs?