Silkies are hard to sex even close to maturity. Before 4 to 6 weeks it is hard to determine sex of even regular breeds. Sorry you will most likely have to wait until your birds are much more mature. I've heard many people say that the best way to determine the sex of a Silkie is when it crows or lays and egg!!!! Sorry I can't be of more help! It's a cutie though, enjoy them!