In Twilight,closer to the end of the book where Balla is in the hotel with Alice and Jasper and she trying to escape from James, Bella writes a letter to Edward saying she why she left Alice and Jasper. What happens to the letter?
I'm guessing since Bella was with Jasper at the time and since he was waiting for her, he would have gone back to Alice and she would have seen Bella escape. So they probably gave Edward the letter when he got to the airport or opened it themselves to see if she said anything or left a clue or something.
My guess is they didn't actually need the letter itself, just the act of writing it. Knowing Alice she would be able to tell what it said with out wasting the time reading it lol