Welcome to Backyard Chickens. If you have any questions, feel free to ask!
Before adding any new chickens to your current flock, please read this article on integration. Adding new birds takes a careful approach; first the new birds should be kept in isolation to prevent the spread of possible disease or pests, then a period of "look but don't touch" should be used to allow everyone a chance to get acquainted without any of the birds getting injured.
Good luck and thanks for joining us!