By 7 months should be about breed weight roughly 3.5-4.5 lbs. If meet weight for breed should be ok. By this age should be on 16% layer feed either pellet or crumble or Mash.
How do you know? How old? Do they appear growing? What are you feeding them? I checked weights on mine and compared to average laying hen weight chart to be sure mine are growing at appropriate rate. I let mine forage in the yard and assume this as extra. Same for kitchen scraps. I’m curious...