She needs to take responsibility for her eating disorder rather then blame you or anybody else. Period.
I get you are excited to see her and be around her. You could reassure that you care about her, and that you want to be supportive but you need to eat. You can't support her at the cost of your own health and being yourself. She needs to face the fact that this isn't healthy for her to have an eating disorder or blame others rather then learn to deal with whatever the issue is with a positive coping strategy.
It's not your fault if she feels triggered. Encourage her to see her doctor and a therapist. I have some struggles with eating, but it's wrong to blame others, because it's my behavior, and my fault, and my poor coping strategy to overcome.
You are not ruining anything. People who have something painful in their past...they probably will have triggers of some kind...it's just going to happen from time to time that one will feel that fear, anger, sadness, and adrenaline and instinct to run or fight. I'm very sorry she is blaming you rather then trying to face the fears and issues rationally and conquer them.
I sometimes would feel fear around large muscular men. I still feel on edge around them. But giving in to fear, rather then calming down and seeking out what makes you feel safe and confident doesn't help. Does she have anything that helps her feel safe or confident or helps her calm down?
