If you have pictures and post them, you can get some idea from the
resident silkie experts.
Now saying that, I could usually tell by 4 months on most of mine.
They had the streamers coming out of the back of their crest,
plus my little roos started crowing at 13 weeks!
On some birds, it is hard to tell and it will take them crowing or
laying an egg to be sure.
It was really hard to tell on mine too. The roos will have more of a bumby comb and the girls will have more of a smooth one. But that's not always the case with ALL silkies. I thought one of mine may be a roo and then she laid an egg
She had more bumps on her comb then my other one did so I just figured it was a roo. Good luck!
I have 2 Silkies that are 8 weeks old...one is much bigger than the other one so I THINK that one is a roo. It was also a little slower to feather out than the smaller one, but now is poofier. It'll probably surprise me by laying an egg