God Loryn, I'm sorry.
I have known several people that took their own lives, and several that attempted it. The only advice I can give you and her is not to dwell on the "why's" too much.... and yet saying that, I know how very difficult it is not to go over those questions over and over in your head.
In the end no one can every really know the total universe inside of the mind of another person; and one short letter, written in pain, is not enough to truly understand the lifetime of experiences, thoughts and feelings that eventually lead someone to make this choice. In the end, you must simply accept it.
