The birds will divide up sometimes according to hatch dates say i have 30 hatch and a month later i have 20 when they get older they remain in this age group and will do so threw out their life here, they do still come together as one flock at times but they have their own clans and i would guess that she was from another clan
So glad they are doing well for you, be careful they can travel a mile before you know they are gone
Thank you for sharing your prettys , i think about Patch every single day so glad he is happy there.