Thanks. It seems to work and yes, they're teeth are really sharp!My puppy is similar, I don't know if this is the right thing to do, but how I deal with it is have chew toys handy and when the feet biting starts I say "No" sternly, get a chew toy, and put that in her mouth, and then make sure she is a bit occupied with that, say "good puppy/name" then I walk away.
If I have time I play a little, praising her chewing the toy, if I'm busy, I have to keep it short and too the point.
a bit like kids really, distraction and a heap of perseverence, and praising good behaviour.
Good luck, their teeth are SO sharp!!