I had that problem with Jake when he was a puppy and teething. I read that when they bite, make a loud "yelping" noise, the same as they do when they are hurt. Then, give them a firm "NO!", you don't even have to raise your voice. Put them down, give them something they are allowed to chew on, and ignore them for a minute or so. They don't like to be ignored. Just keep doing this until he "gets it". You have to be consistent, they learn by repitition. Always make sure she has enough to chew on. Bully sticks are great for this.
Jake would bite at our feet, especially if we had socks on. I put a little "Bitter Apple" on my socks, and he never did it again. You can get the Bitter Apple at any pet store.
Hope this helps. Good luck!!!