Thanks everyone. When I got them, two had very pronounced V shapes on their heads and two did not, so I thought I had two male and two female. But as they got bigger all three started looking like this and the other did not survive.
This is a 12-week old Bantam Welsummer. I have two that look like this and one that is slightly larger with long green curved tailfeathers. Is this one a pullet?
Thanks. I thought I had only one RIR cockerel, but I guess I have two. Below is a photo of the other one, also 12 weeks but with a bigger, redder comb and the feathers around the neck are pointier and with dark tips.