I have some EE & a variety of other chickens hatched at the same time. I kept them all together away from my older hens so i would know exactly when they would start to lay. I sold some of these birds at about 12-16 weeks. I told the buyers they could lay as early as 16 weeks and up to 20 weeks. Meanwhile one of my EE escaped and ran with my mature hens. She started to lay at 19/20 weeks. I waited another 4 weeks for my cooped hens to lay. 1 hen started to lay and I waited another week.... Then I took all but 2 roosters from that hatch out of the run. 2 days later they started to lay. Different circumstances of the birds gave me different results. The hen that escaped and was out on grass that could get away from my roosters layed at about 5 months. 35 confined bird with 5 roosters took 25 weeks.