I have 17 two months olds and 12 adults separated by chicken wire in the adults coop.
Yesterday I went out and one of the babies had flown into the adult coop and was eating. I don't know how long she was there but everyone was fine. I put the baby back into her own coop.
Today, I went in and found two had flown over to the adults. Again, I don't know how long they were together, but everyone was fine. And, again put the wayward babies back where they belong.
They have been looking at each other through the wire for over two weeks and I think they are getting used to each other.
At least two of my hens are broody and seem quite interested in the babies, always going to the wire and talking to them. I'm going to keep this up for a bit longer, at least till the babies stop sounding like babies and see how we do.