This is a very simple thing to fix. Offer your hand, when she bits, pinch with your thumb under her tongue and your fingers outside of her mouth under her chin. Like you are picking up a Bass.
she doesn't need to yelp, but be firm and make her want it to stop, she will back away and open her mouth. Tell her "No Bite"
Keep at it, everyone in the family needs to do it.
Labs have to bite things, they have to, they are mouthy dogs.
Never ever give your dog rawhide, unless you want a very expensive trip to the vet. Soak a rawhide chewy in water and watch it swell up, then imagine the rawhide they swallow.
Go buy a Kong, put some pnut butter in it, that is what they can chew on.