I'm impressed that you know which egg goes to which hen too. I have seven hens, one lays green, one olive, one blue, one*big* brown ones (red star sex linked, I know they're hers because I added her to the flock later), two light brown and one medium brown. I know which of my EE *doesn't* lay the blue one, but hadn't differentiated the two greens back then. I probably have the slowest lay rate from my blue egger. My original six hens were all given to me laying already, and he said one was older than the rest, a couple years maybe, but didn't give any more details. The rest are about a year old now. I'm working on differentiating lately, tracking which colors I'm getting each day, but it's hard to catch them in the act.