MITES ON MY SETTING HEN!!!!!

my very small banty hen decided to set on 5 eggs. its bout 17 days into incubation and her eggs are starting to peck(you can hear them pecking) and when she cam off to eat some food her eggs had little black bugs crawling on them and in the bedding around it so i got another nest box spayed the bottom(its plastic) with mite and lice repellent made for chickens and put bedding in the new nest that was coated in DE , then i looked at her vent and some of her feathers were coated with mite eggs and mites. i cut those off and threw them in the woods and i scrubbed her with seven dust but i am afraid if the chicks hatch they might get the seven on them and cause major health problems. what should i do!!!! by candling them they should be due in a couple of days please help!!!!!!!!!!