SEX-LINK

[cmom]

It's hard to tell by the picture. I can't really see the comb too well to tell if it is a pea comb but looks like a single comb to me. I agree it doesn't look to be too well feathered for 3 weeks.

 

[Habibs Hens]

to me that looks more like 1 week feathering

 

[BrittBergh]

My one black sex link was a slow grower, my first post here was about her slow growth actually!
They look normal size to me and they look fine in my opinion! Mine is 11/12 weeks old now (I forgot) and as healthy and spry as any of the other chickens we have! She is a lover too loves to sleep in my lap!