My new leghorn (5 weeks)has issues getting used to the other Chickens(2 that are 6ish months) because one of my older chickens pecks her and used to attack her. Any suggestions on getting ten used to each other?
She is too young to be in with grown chickens without a mama hen to protect her from my experience. I'd put her in a separate area for now and try again later.
Hello and Welcome To BYC! X2, it is best to wait until the younger bird is about the same size as the older ones and then have a long period of the two flocks being able to see each other but no touching, through wire seem to work best, ie dividing the coop into two sections or keeping the new/younger ones in a cage inside the coup for a couple of weeks to a month at least. The chickens will get to know each other and sort of work out a pecking order before actually coming in contact with each other. After a week or two, letting them free range together is a good idea and should help... It will take a couple of weeks to get the pecking order sorted out. There is a nice article in the Learning Center on integrating flocks you might like to check out, the part about actually combining them is after the quarantine section https://www.backyardchickens.com/a/adding-to-your-flock and a nice article using the wire method https://www.backyardchickens.com/a/introducing-new-chickens-using-the-see-but-don-t-touch-method