Why don't you report her? Surely that is abuse/ an abusive work situation?
You could forward the messages to your supervisor.
Ahh corporate America, it has its blessings and its banes. I have learned that the one who reports trouble can quickly become the one who is labelled as trouble. Turns out, she is always reporting on others. HR will catch onto that rather quickly and turn it on her. I will just wait and be there to provide some "background."