In the past, I have let a mama stay in the coop with her chicks and other chickens. Never had a problem.
But, this last hatch, the eggs kept getting pecked and eaten. So, I pulled the mama's and eggs, yes, two broody hens sitting on same eggs.
Then, when they got a little bigger, i would let them free range. the mamas took the babies back to the coop, so I let them stay.
One morning I went out and there was only one chick, not two. I couldn't find the other one anywhere, figured it escaped or something, I didn't know.
Oh wait, this is a horror story
the rest isn't good
I'll just add, next time I will NOT let the chickies in with the older hens.
One of the very older hens, became aggressive in her old age, she is nine years old now.