[MyPemCharlie]

Number one, stop growling at her. Someone gave you bad advice. She either thinks you are being aggressive (and that is scaring her) or she figured out that you're not really being aggressive and she thinks you're play-growling. Either way, growling is going to encourage her to nip more.

When she nips, try screaming a higher pitched "Owww!" or "Ouch!", then say "No biting!" in a very serious tone. The "Owww!" should sound like a dog squeal when one litter mate bites the other too hard. That should stop her at least momentarily. If she keeps at it, repeat the "Owww! No biting!" then walk away from her. No playing or attention for a few minutes will make her realize she did something wrong. If she keeps coming after you, you may need to have her "time out" in her kennel, bathroom or kitchen for several minutes.