The babies are no longer little balls of fluff. In fact at only one month old they are getting too big for their habitat in the garage.
It's time to introduce them to the big girls. But these introductions need to be handled delicately. A good option is to wire a run within a run so the girls (both little and BIG) can get used to each other without access to pecking each other.
Eventually, when the littles grow some more, they can mix it up.
It's kind of like hardening off seedlings!