Her email response shows you exactly where she is at. She doesn't see anger as destructive she sees it as a tool to get what you want. Not a very healthy way to look at it.
She is right, anger is a part of us all and it does serve a purpose but she also said "Because how we manage anger or choose to express it is the problem, not anger itself."

I believe that is correct but she isn't seeing the real meaning behind the statement. She doesn't see a problem with how she uses or expresses her anger. Again, it's a tool for her to get what she wants and IT WORKS!!! Why should she change. She won't until she sees that the way she is using and expressing anger is destructive and hurts people.

I feel bad for you because I know that you want to help her and you care about her. The thing is she has to see some of it in herself first to even begin a change. I don't see that she is anywhere near that.

I hope you will think about what is best for you right now. She needs help but I don't know that you are the one to give it. She will only take your spirit and destroy your life. You don't deserve that.
Hugs,
Heidu

When one door closes another door opens; but we so often look so long and so regretfully upon the closed door, that we do not see the ones which open for us.- Alexander Graham Bell