thanks for your response, the chick with the biggest combo which is the one that it suppost to be the Roo is a week younger than the one with the smallest combo, the one with the big combo has little to none tail at this point, the hen has a long tail, not sure if that helps
I only hatched lavender orpingtons once, but hatched 16 and sexed them by tail feathers with 100% accuracy. A week age difference at this point can make a difference in tail size. The comb on the latter is much bigger, so I would say without seeing their tails your guess is probably accurate.