It's hard to tell, but #2 is definitely a pullet.
If you go simply by comb size, #2 is the only one that looks like a pullet.
My guesses:
1. Pullet
2. Pullet
3. Cockerel
4. Cockerel
You can see the similarities in tail shape with #1 and #2 (pullets?) and #3 and #4 (cockerels?).