Don't raise Chicks with Broody hens if your that scared of your Cats.?...I never worry..My Cat is a hunter..She kills Bush rabbits, Magpies, squirrels and song birds....Never one of my Chicks..
I didn't have anything to do with it except try to provide them a safe space. Chicks happen, apparently.
Sorry...I did my best to explain how to handle Broody Hens and Chicks....You never took any info as real and implied them....Sorry but I do know how Chickens operate and they are total beasts...
Best wishes.....I wish things went better..
Also....Chicks do not just happen if the care giver is not letting it happen..