I believe your "she" is actually a "he", and looks like a Barred Rock with some other breed back there in the parentage somewhere. I see evidence of sickle feathers on the back, maybe some pointy tail feathers beginning to grow, sickle feathers around the neck (which I've never seen on my BR hens), thick legs, and a bit of red feather "leakage" on the shoulders. Also, BR cockerels tend to have a black & white pattern that's pretty sharp and distinct, with more white than black (definitely see this around his neck) - while hens will have a more mottled or random pattern, with more black than white. In my flock, the BR combs and wattles are always slower to develop than the other breeds - so it's not surprising to me that your cockerel doesn't have a rooster comb yet, even at 4 months. It'll come. He's a pretty boy!
