After a week of thinking...and saying...I couldn't do it, I finally mixed my 2 1/2 month old EE's with my 8 other pullets, 4 - 5 months old. They have been in the same run together for a month now, separated by wire. Today, after getting completely frustrated with trying to build a coop within a coop, I let them all out together and walked away. I was close enough to step in if needed...and to hear the horrible screams now and then, but tonight they all went in the coop together. There are a lot of feathers blowing around the run tonight, lol and there was a lot of jockeying for the best roost position, but everything is calm now. I'm going to go back out with a flashlight soon and make sure and I'm keeping my fingers crossed they all come out ok in the morning. I think I made this a lot harder than it should have been but it was difficult!