If you look at the first pic, the barred one in the front, you can see the comb is larger and redder than on the other chicks. Looking at the same pic, look at the RIR in the upper right, you can also see a larger comb on that chick. In the last pic, the RIR futhest to the left, you can see a more developed comb. It's hard to tell, but pics of each chick would make it much easier. Like others have said, it may be a while before you know for sure.

