Can you tell what breed this is and if it's a cockerel or a hen? (Pics included)

[Habibs Hens]

it looks to me like a welsummer

 

[ACargill]

At what age can you usually tell for sure if they are pullets or roosters? I've only heard the small chick even attempt to crow; the others still peep.

 

[myhubbycallsmechickeemama]

I think the little Bantam is a cockerel but I don't think the RIR or the black and white one are.