Hi, I got my first chickens in April. An austrlop, a barred rock and 2 buff orpingtons. I think the two black girls are getting ready to lay, they are 22 weeks, the orps are 21 weeks but don't even look close to mature? Is that normal for them to be so behind developmentally? I'm in texas, could heat be a factor? They ate starter feed till last wee, now they have layer feed and are free ranging. I'm worried about they orps. Overall they are fun, only the barred rock lets me get close and pet her.