Bantam cochins (or pekins) can often be hard to sex until they get a bit older. I have a pile of them, and while it was obvious for some, for many I really didn't know until they were about 8 weeks old! They can be a bit slow to mature.
Looking at your two, I'm not sure on the combs, but the upright stance and the curving tail of the one in front in the second-to-last photo might be indicators of "boy"- could just be the angle of the photo, though. Nothing about them is screaming rooster to me, but the other experts on here might have more opinions.