Comb color (pictures) and how soon should I expect an egg?

[Justhatched]

I have 2 16 wk Barred Rock pullets with a 21 week old Barred Rock cockeral (and 2 other cockerals I am rehoming). One of the pullets comb is darker then the other and I saw ther cockeral mounting one (from a distance so not sure what one). Should I expect the one with the darker comb to lay soon? I didn't expect that for atleast another month.




The cockeral with each pullet.


The pullets side by side.

I raised them since they were days old.

 

[Glasshen]

One does look more mature, and Ive noticed that in my birds too. One way to see if a pullet is getting ready to lay is if she does the "egg squat." sometimes they will squat when you just walk up to them, but if you put your hand down over them, kind of knee height and she squats, it won't be too long till you are getting eggs. And 16weeks would be on the early side, but it could happen any time now.