Looks like a hen to me, but it is difficult to tell with that picture. Any way you could get a close up shot of his/her body and head?
Basically what you want to look for are pointy saddle (rump) and hackle (neck) feathers. Also, the tail feathers will start to come in with little points and eventually they will curl over. You can also look at the comb (fleshy part on the head). If it is large that is a good indication of a rooster. Usually you can also tell by the color of the comb (More red at young age = rooster). However, it looks like your little guy has the dark skin of a silkie so that may not be a good indicator.