I think she's trying to keep them under the weight requirement for fair?
You should see my meat chickens. I got them as month old birds at the auction for the same price as day olds. They have not acted like meat chickens since they stepped foot on the property though, they spent much of their first month escaping the pen. Over and over and over again. I finally threw my hands up in the air and said, fine, free range if thats what you want!
I don't think they know they're meat chickens, since they run with all the rest of the flock/ducks. I do think they grew a whole lot slower, of course, I didn't have to feed them obscene amounts of food either. On the plus side, meat chickens will eat anything, and they clean up all the rabbit pellets the buns spill or anything I dump out.
The down side is that they taste just like the other chickens do, still gamey and chewy.
The funny thing is everyone who comes here for other stuff always asks about them, and how did I get my Meat Chickens to DO that, since theirs all do what they are supposed to do (Sit, eat and poop)
Which of course doesn't help you keep your birds under the weight limit. Maybe just feed them some fresh greens? Fresh veggies? Are you feeding them free choice or limit feeding? I don't free feed anything, well, other than chicks still in the brooder that is. I feed mine once per day (I've been feeding the ducks twice a day, they are just insane with the amount of feed they can put away!) after that, I tell them to go find some bugs to eat!