Long story short we were left with only one hen. So we wanted to get her some company and came home with three pullets. One is 12 weeks old the others are around 10 weeks old. I have a coop that the hen sleeps in and I fenced off the entrance to the run so the pullets live there. I put in a roost and food/water. The hen is now in the yard all the time because she cannot get into the run. We usually kept her in the run and let her out into the yard once a week or so.

When is it OK to let them all live together? I am concerned that the pullets will be easy targets for a hawk so I don't want to free range them until they are full size. But when can I remove the hardware cloth from the run entrance and let everyone mix and eat and drink and sleep in the same space?