Hatchery polish can be misleading. Girls should have a "bouffant" and dudes should be "spikey". Hatchery girls will sometimes be spikey too. Look at the waddles. My males have had waddles right away.
Spikey Stink-eye (was missing some top feathers at the time)
Hatchery Hen. Not really "poofy" but I have hatched her chicks, so we knows she's a girl.
Hynotized hen. She she is "poofy" and "roundheaded"?
someone here posted photos of 6 week olds and ones wattles were already larger and redder compared to the other (she had 2). i think it takes quite a while to be able to tell by their headfeathers (hens have more of a poof and roos have dreads)