Help not sure if what breed this is...

[GayEgg]

Leghorn.

 

[Gray Farms]

I'm going to say with that cockerel at 2 weeks old having that much comb growth they're white leghorns.
Also believe the other two are pullets.
Can't see a late bloomer cockerel being that far behind the one.

Agree completely. My first thought from the pics was White Leghorn. All traits of these chicks points to White Leghorn.