Oh I so understand having an established flock wile they are young and I hope this all works out for you and so sorry about your young pullet turning out to be a roo ......
One of my young lady's with her chicks and I know there is going to be a lot of crowing going on this fall ...
If you take the photos here and blow them up to a 300 + and look at the saddle feathers you will see the beginning of pointed feathers and look at the neck feathers you will se he is maturing fairly fast ........
Good luck with your poultry