This is what I told her- it's the best I could do, because my original email I sent was sooooo long and upset.
"I have so much to say, that I know you'll never be able to deal with it. You will miss points and notice redundancies, etc. in my original post.
So let me say that, basically, I hear you making a lot of excuses, that somehow, you're trying to justify putting my father and my husband in bed together with talk about fixing my anger that I misdirect at XXXXXXXX, improving my sex life with my husband, and getting rid of my coping mechanisms of compartmentalization and others.
I could write 1,000 words, perhaps I already have, and not maybe get you to understand, what it's like to be me, what it's like to be triggered, what it's like to have that worst-possible-case scenario/nightmare in my head. You have defiled my personal, sacred space, that I have painstakingly created around my husband and our life together. You have blatantly ignored and trampled through my valuable defenses, which I took down to show you something that I really wanted help with.
I am deeply deeply hurt. There is no point you could have made to justify the ugly image. It's very cruel to me, I feel, for you to hurt me so, and tell me it was in my own best interest, to defend it as trying to help my daughter.
I am begging you to reconsider your explanation. What you did could not possibly have helped me with XXXXXXX or XXXXXX. I do not believe those sentences were anywhere near the best you are capable of, and I am praying I am right, and that you will make this right."