Mine from post #24 turned out to be female too. I was shocked, but pleased! Maybe something in the water this year, making them hard to identify early. Never had such a time!
It seems to be the lavender variety that is a troublemaker. They sure keep you guessing. I never had a problem with my buff or chocolate Orpingtons telling the sex quite early.
For me, it was just this batch of lavs and part of the trouble was that I was expecting 50% male (not 13% or 1 out of 8). Another part could have been the weather. Perhaps chicks mature more slowly in late fall.
Normally I can guess by 4 weeks & usually confirm by 6 weeks. The only male I got just happened to be a very late bloomer.
Here's the confirmed male at 5 weeks (long before it was confirmed).
Here's the other suspected male at 5 weeks
(the one which I now think has grown into a female)
What I didn't realize then (at age 6 weeks) was how many females there were. This pic was taken after I sold the 1st 2, whom I was sure were female. Only the Purple (on right) turned out to be male. The dark blue (left) is the other one I kept.
Here are 2 pics taken last spring of what my males normally look like by 6 weeks:
There's usually very little doubt.