you will want close UPS of their face, so we can get a good look at the comb. Silkies can be tough to figure..mine are the same age and wev been back and forth on them!!
The white one looks like it has no wattle development at all, and male unbearded silkies usually have obvious wattles by 13 weeks of age. So I'm not convinced it's male. A head-on picture of the comb would be helpful.