I would say female as well, judging by the facial structure of my male silk when he was that size. My female, on the other hand, looked very similar to yours. The good thing about silks is that they have pretty good genetics, so if yours isn't showing signs of a kok in great care at around 3 inches, it's probably female. This still isn't definite, though. It still may be a male, but my shot in the dark says it's a girl. Also, you can see the tube in the third picture a little bit, and it doesn't look too thin.