RIR Gender?? image heavy

[willow13]

I have 6 RIRs that are about 2-3 weeks old. I'm not sure if they're too young to tell at this age though. I am curious about one in particular though. It is smaller (the 2nd smallest), but is much slower in growing its feathers. All of he others have started growing their tail feathers and wing/back feathers a few days ago, and they're getting larger, but this one has not even started getting its tail feathers in yet. It's also the loudest. If you pick it up, it flips out, flaps like crazy, and screams so loud it hurts your ears. After putting it back it continues its hissy fit for another couple of minutes lol. The others do get irritated when held, but not like this one. They are all "supposed" to be pullets. Any ideas?
The first 2 pics are of the one that I'm not sure about. I have two that are double the size of the rest as well. I don't know if this pictures are close/clear enough to even tell anything, but any guesses would be helpful. Thanks.

 

[tracylhl]

I'm no help other than to say that I have 4 RIR's that are all 6 wks. that were supposedly vent sexed and all pullets. One of them seems be be maturing slower feather-wise but the comb and waddles are just a little larger than the other 3. I think that one might be a roo. This is the first time I've had chickens and know very little about them so I've been searching this board for the last hour trying to confirm or deny his roo identity.

 

[stormylady]

Im not good at quessing sexes, but just had to say what cute babies you have there. I love the abvionce(spelling?), in the last 4 pictures. Sandy

 

[willow13]

thanks

lol