I don't believe much can be done. Either she falls for you, but if she is aware of your feelings and has been for quite a while then I'd gamble on that. Life's unfair and harsh, nothing can be done about that. I agree with
>>2.
If she might want to commit an act she might regret it's still her choise, unfourtanly you got nothing to do with that, express your fear if you want too but don't push it too far.
Mistakes that gives birth to regret gives us value experience, we develop cause to them.
Still, I wish you goodluck with her :)