We are human nylabones

Remember how I was gushing about the puppy? I still love her to bits, but she's chewed my heart into a million pieces. She's been biting us, hard. She drew blood on Leon at least 4 times already and it doesn't seem to be getting better. We're doing everything that the books tell us to. Yelp, have a time out, leave the room. The yelping seems to freak her out and then she bites harder. The time outs and leaving the room just direct her attention to other items in the room we leave her in like her bedding or her wee-wee pad. I really feel like these methods are just not working at all. Am I being impatient? How long is this supposed to take?