The growling/soft clucking is normal for a broody. Mine always do that, but thank heavens, I've never had one mean enough to actually bite me!
Has she been eating and drinking enough? You need to make sure she is eating and drinking. I had one broody back at Easter time that just about died because of her persistence in hatching the eggs she was sitting on and not wanting to eat or drink. I offered her mealworms, strawberries and yogurt, canned corn, broccoli, slices of apple, etc... Anything to get her to eat and drink. Watermelon would even be good at this point, because it has so much juice in it. You'll be wiping out two things at one time!
Good luck with her! I know how frustrating it can be.
