hummm.. first, I'm glad that she wrote you back. Do you feel like she's being sincere about it? Because I feel it this way but there's no way I could know for sure as I don't know your t...

There are some things that you remember incompletely, or inaccurately, but you do have to go on your perceptions and your memories and your feelings.This made me thought that, hey, if you remember stuff inaccurately, she surely does too. That's being... human being! Everything is perceptions and two different persons will always have two differents perceptions.

How do you feel about everything else that is written in it? I think you could talk to your current t about it, but if the reference thing is bugging you, you could send the email you found telling you that she suggests you staying with her, if you feel you need that to have closure...
I don't know all of your story with ext so take what I say next with cautious (or forget about it if you're not there yet or if it's not useful or don't read it at all): if you feel she's being sincere about what she wrote, you could also tell yourself that she truly wanted to help you but she made mistakes and that her perceptions of what happened is incorrect but it wasn't intend to hurt you...

take care
faith