@Rick589 , I had multiple integration problems like you describe for several years with all my juveniles, while there is enough space for 8 hens and a bunch of chicks. Adding roosts didn’t help. The older hens just wouldn’t accept juveniles. Not 1, not 10 and nothing in between.
Last year I decided to buy an extra coop.
Again the mama and her 3 juveniles tried to sleep with the other hens. But no. No way they the juveniles were allowed in the adult coop.
The family started to roost in the small broody coop until it got very cramped. Some time after I finished the new coop, I took the family from the roost in the evening and put them one by one in the new coop.
Next day the mother and one juvenile went into ‘their’ new coop by themselves (If I remember right). I moved the other two juveniles a second and third time and maybe a 4th time. But within a week they all roosted happily in their spacious new coop (a converted children’s playhouse) .
Never had any problems or arguing since.
sometimes the chickens trade places. The chickens divide themselves between the 2 coops 4 + 4 or 3 + 5.