Unless her teeth are made of titanium, I doubt you've got anything to worry about. Even Pokémon have their limits.

[He chuckles. At least Rin didn't get stuck with something that knows Fire Fang. That would stink.]

But you could always try grabbing her by the jaw and carefully trying to pull her away. Might not be the best route, but at this rate I'd recommend changing tactics until you find something that works.