Megan,
It's called a phone. Use it every now and then.
We are having the same problem with Prince. We finally figured out why he was biting. Mostly, it was just play, but every now and then he was getting scared with Jeremy and just biting out of fear.
I know your dog, and I don't know why she would bite, unless it was because you had the smell of food on your hand. Sit down and think about what ya'll were doing. Were you playing rough? She could have just been playing and bit a little too hard.
Just keep fooling with her and see if she does it again. And for safety, keep Mary Hannah away from her for a while. Knowing the temperment of your dog, I don't think she was really trying to hurt you.