I would agree that Shellie is correct.
And yes #3 looks like a Cuckoo Maran mix to me (hen) the only reason I would say "mix" is due to the gold color feathers she looks like she has around the neck. Bet she will lay you some pretty brown eggs.
The only one I think could possibly be a roo is the silkie. I don't know silkies at all, but the rest look like pullets. The white leghorn is for sure - pullets have floppy combs, and cockerels have straight.