Yes...the trick is to be well-timed. I have tried the vigorous facial/muzzle rubbing with my mouthy gelding, but oddly enough he liked it. Perhaps I wasn't rubbing vigorously enough? Lol With him, the biting is more of a game, as he flips his head up immedietly after so I can't pop him. But the last time or so he tried this I swung the leadrope at his face and smacked his nose with it, and he hasn't bitten me again...nor has he turned head shy.
His first and last real bite, he landed a good chomp on my arm and I now have a rather large and deep bruise. I'm not going to tolerate it. I think that particular bite was an issue of respect, so he is not allowed to be mouthy, playful or not. It took me bopping him in the nose and I wouldn't think twice about doing it again.
You are doing the right thing in letting her know this is not acceptable behaviour with humans, thin-skinned delicate weaklings we are, as it has a chance of escalating as she gets older.
Let us kow how it goes.