Once a hen is broody she stops laying so nothing to worry about there.
many people say it's not possible but I have hatched eggs that were in the fridge for a week then sat ou on the bench for another week before I could set them.
First thing to do is make sure they are pointed end down in the carton and get them up to room temperature by leaving them out of the fridge at least a day before putting them under her. If you have other hens in the coop you may want to section the broody off or move her to a separate pen or "broody pen" to prevent other eggs ending up in her nest or eggs being crushed in scuffles. Hope that helps, good luck!!