If you want to be able to handle the babies once they hatch without the Momma taking your head off, pet her now. While she is broody, if you'll pet her while in the nest every day (even if she hisses or pecks at you) she will learn to trust you and after a few days you should be able to pet her back and head, give her treats by hand and her not make a stink. Then once the babies are born, after 3 weeks of petting her, most will trust you and won't hurt you when you pick up the babies. But there can always be the exception with chickens.