You do know different breeds develop bigger combs or not right? Like right now I have brahmas and none of them have combs but that doesn't mean they are all girls.Yes, I think all four are girls. No I am not familiar with SFH. I think they are girls because that is what my first chicken looked like when she was little.
You raise SFH? So you guess is the only pullet is the lightest one? Other 3 boys? :-(Crested are always harder to tell. But the blue based one looks like a cockerel. The lighter one a pullet. The none crested both look like cockerels. I do raise them, but I would wait intill seven weeks before making a real judgment.