Mine are past that stage. Mine are all feathered. I know what you are talking about because some of them do feather faster. Does the body size mean anything? I have someone coming now in the morning to buy 6 of them and I really want to keep a couple of the females. I have some that are noticably smaller in stature and size. I stood out there and looked at their wings for a long time. They all have feathers now. Some of them are not filled in as much towards the bottom of the wings but for the most part they are all feathered and past that stub stage.