I am just updating this thread - that's exactly what I did. I kept putting them up on the roost together, and they got the idea pretty quickly and were roosting on their own. I also changed the feed so that I was only feeding starter/grower and oyster shell on the side.
So far, one of the two...
I have 4 point of lay (but not yet laying -they look close though) pullets and 2 older hens (2 years old) they are in separate coops. During the day I have put the pullets in a little baby yard covered with chicken wire, and let the hens free range, and they seem to have gotten used to each...