Hmmm having never brought new chicks in to an existing flock, I'm not sure. My guess is that she would not take to them.
I understand from reading that you can slip a chick under a broody hen and remove an egg, but I don't know about a group of them, or since she's not broody if that will work.
I'd probably ask around before doing that.
She sounds like she's doing good thought despite all her adventures!