3rd times the charm?

[Egrossman104]

Do you think it would be possible to integrate a 4th pullet (once the cockerel is gone) into the flock? It was easy up until now because all of the chickens I got were from a friend and they were all born and raised together so adding and taking away hasn’t been a factor. I know there is typically a pecking order. The real question is should I just be happy with the 3 I have or can I add a 4th? Just looking for general advice. They are Brahma mixes if that is a factor.