I would give it one more week and see if the comb continues to grow and / redden. But again, I'm not an expert, just someone who thinks that as a general rule rounded hackle feathers can indicate a pullet in many breeds. And I wouldn't want to give away a pullet just because I didn't give it enough time to be more confident of the gender. I may be totally wrong, and everybody else is right, though. I'm just saying it's still a guess until he / she crows or lays an egg.
