IMHO, I wouldn't send it tonight for a variety of reasons. I don't want to sound negative, but if you do, she is only going to see it as another attempt by you to sway her. That may NOT be your intent, but it will likely come across as that way. I would write the letter, file it away and save it for a day when you're both removed from the sitch a bit further. Think of it this way, what do you really hope/want/see happening by sending her the e-mail? Do you have an expectation of her reaction formed in your mind? Even if you don't what do you think, expect her reaction to be? If she doesn't ultimately respond, will you be affected?

I really wish things could work out better for you, but I understand what you are going through. Good luck in whatever decision you follow.

"Achieve success, but without vanity; Achieve success, but without aggression; Achieve success, but without gain; Achieve success, but without force." Lao Tzu