You may have to build them an additional roost... it could be a shelf instead of a bar if you want, I often have the youngest in the coop roosting on sand shelves below the level of the 'big birds'. Just make a 'picture frame' out of 2x4s in the desired size (maybe 1 foot x 2 ft) then tack a piece of thin plywood to the bottom of it. turn it over, attach legs to each corner, make it tall enough to maybe straddle the opening to your nest boxes but preferably low enough to be slightly lower than the other roost bars. Set it in the coop, you may need to put a screw through the back of it into a coop wall to make it more secure... fill it with an inch or two of sand (you can add some PDZ stall refresher to it if you want).... having a wide shelf allows the mama hen to move the chicks up and either cover them while they are setting on the flat sand or perch with them on the edge of the shelf.My broody and her two chicks are still sleeping in the nest box, and it is making for a mess! I think she wants to take them to roost, but the other hens are pecking the chicks on the roost, so she takes them back in the box. The chicks are just over four weeks old, and are ready to roost, but the big girls aren't making it easy for them. They don't mess with the chicks during the day, but night is a different story. Honestly, there isn't enough room on the roost for all seven of them. While they physically fit, it is pretty tight quarters. The coop was designed originally for four-five birds, but I could maybe add another roost in a pinch. A smaller coop isn't that big of a deal here. I live in Florida, and the girls are never inside unless they are sleeping or laying their eggs, but I don't want to be cramming them into a tiny house. I do have plans to make a larger coop soon, I have a wooden playhouse that I'm going to convert as soon as I can get it to my house from my friends place. I guess I will just have to deal with a dirty nest box until then, because I don't think she will take them to roost with the older hens picking on them.