It took me probably four months to know for sure a girl, when the boys' tail feathers were growing longer and hers were not.I've never been this unsure. Normally I can guess at 4 weeks & confirm by 6. The hardest one took me 8 weeks.
Their wattles say male & the combs say female.
Now I know you can't always go by the size and redness of combs and wattles.