More chick ID

[Akrause57]

Brought these three from TSC, were all labeled as Barred Rocks. Last one is developing much more than others, but also think she might be a roo. Any chance the other two are different breeds, or just slower in developing? If they are different breed, what?

 

[Rainwing]

with no stripes and such a dark beak i would think a black sexlink, since they have a white patch under their beak for a while as chicks. black sexlinks are bred for egg laying/sometimes dual-purpose and are a cross between a RIR or NH roo/barred rock hen - in that case most likely a female if it is a black sexlink.

if it has brown feathers mixed in with the black feathers it is most definitely a black sexlink female. (it kind of looks like some brown feathering on its wing in one of the pics, but idk)