I wanted to get some thoughts on this. I have a couple new birds and one (3months old) I suspect is a roo because I feel some nodules on the lower legs. I think that these nodules are the little spurs coming in, there hasn't been any comb growth though. The other morning, I was letting the birds out of the coop and this new bird came down the ramp behind Eli, my big Roo. Once they got down the ramp Eli turned around and started strutting for and around the new bird, just the same as he does his hens. So, based on how Eli is acting, is it possible the new bird is a hen even though he/she has the nodules?
I had some buyers come by with their 5 month old silkies that I sold them as babies. They thought they were both girls because their roo was breeding them. They were both boys! I wouldn't put any stock in the nodules. Girls can have them too, they just don't develop into spurs. Spurs develop way later.