Oh, I feel your pain
Kalani learned very easily that I do not want him biting or playing rough just by me saying 'ouch' and putting something else in his mouth. Hoku, on the other hand, was very stubborn and I had to be firm in my tone and show her who was boss by holding her down for a couple seconds when she challenged me and then turning my back on her and ignoring her for a few minutes. Believe me, she fought me twice till she realized I was serious and not playing. After that all I had to say was either 'no biting' or 'I'm the boss' and she would immediately back down.
Good luck, just be persistent and don't discipline her when you're angry or frustrated because they pick up on that right away. What you're trying to teach is what is appropriate behavior and who the 'alpha' in your home is
