Ms. K was talking about a particular method on another thread and I realized it could help here, too. Folks will set up a "one way gate", where the spaces in the fence allow smaller birds in and out, but not the full grown hens. You could put some feed and water behind one to make sure the little ones have unimpeded access to it.
I couldn't find a good picture for some reason, but it would end up looking like this, maybe a little taller.
Can't you just picture those little ones flitting back and forth while the big girls are stuck on the one side.