Mine generally lay at 5 months,some 6,but other factors play a part here.The time of the year hatched and the amount of light. My late hatched pullets lay a small egg and gradually it gets bigger.Having artifical lights helps with laying and is a big factor,also feeding a good laying ration that is not diluted too much with grains,like to keep layers on 80% layer and grains,leafy greens,table scraps,and treats the rest of diet..Sometimes the birds get the egg eating habit,if the nests are not dark enough,not enough nests,frozen/cracked eggs,or eggs not picked up often enough-so you think they are not laying but they are only eating them.Use fake eggs in nests.