Well I had a ton of broody hens last year so I really shouldn't complain but it is what convinced me it was time to take a break from hatching. I lost count of how many broody hens I allowed to raise chicks last year because a couple of them went broody twice but it was somewhere between 6-8 broody hens. I tried several methods and most went well. I had broody hens that raised chicks in a broody pen that was next to the main run for a few days before I allowed them to integrate, I had co-brooding hens (adorable!), I had hens that hatched and raised their chicks in the main coop with the rest of the flock, and I also gave newly hatched chicks to broody hens. All of it went great until my last broody hen of the year.
I can't be 100% sure what happened when I wasn't watching. I gave the hen 1 egg to hatch. When I found the chick hatched it had been seriously wounded, I think it was by another hen in the flock but the broody didn't protect the chick properly either way so I ended up bringing the chick inside (and I eventually rehomed the hen with someone that didn't want hens for brooding). It was touch and go for a while and I wasn't sure it was even going to survive at first...it was floppy and seemingly lifeless for a while. Once it started to come around I then I started caring for the slipped tendon. I was unsuccessful in repairing the tendon. The chick survived and you could say he even thrived with one functioning leg, we named him Peg Leg Pete, he's with a special needs boy now that absolutely adores him. You could even say everything happens for a reason and it was a happy ending but it was at least a month of ups and downs for me caring for him and teaching him how to chicken, then integrating with the flock.