Well, it sounds like you are making progress in a challenging situation, so good for you. I still love your avatar. It is the perfect snapshot of doggy joy.
If she is "just" a nipper, you might be able to find an experienced dog walker who can take her on. She might need to be the only dog on her walk and handled carefully, but it can be done! That might help with her aggression issues, actually. Just a thought.
Also, does she use the pee pad in front of you, or do you always take her outside? Maybe she's just not trained to use the pad?