I agree that these chicks look younger than 8 weeks. Who told you they were that age? At about 4-6 weeks there should be signs as to their gender. Look at feathers on back (roos have less) and size of legs (roos are larger). Be patient. Time will tell.
I have had these chicks for 5 weeks total and the lady said that they were 1-2 weeks old when I got them. So, they are all at least 6 weeks. So, maybe 6-7 weeks old. Opps. But, I have some that have completely feathered out that are alot bigger than this one. He is one of the smaller ones. Is it possible he's a banty?
Are all your guesses still staying the same given that I was off on the age a bit? The lady sold me 10 chicks- some she hatched and some she got from the hatchery- but they've been together all along.
looks like a pullet, but like the others said, it looks younger. It looks like there is quite a bit of down on her yet. Mine are around 7 weeks old and are quite a bit bigger, and the down is pretty much gone.