Ignore the advice which others give here to approach her directly. That too is a recipe for disaster. She will use this "one-on-one" time to drum up additional charges against you. You cannot reconcile with her. There is nothing you can say to change her behavior.
You need to go on the offensive, hard and fast. Document everything. Go over her head. Do not back down. Do not let yourself be intimidated. Stay calm, cool, and collected, and then, when you have everything you need, file charges against her with management.
The goal here is to make her toxic behavior rebound back on her. Do not feel sorry for her. She can end this at any time by changing her behavior. Remember: she is her own worst enemy. You are not the problem. She is creating the environment. She should bear the consequences.
If at all possible, foster an "I don't care what you think about me" attitude when it comes to whatever garbage she invents about you. This is to insulate yourself from your own emotional reaction, which will only damage your case.
Remember: Your goal here is not to reconcile with her. Your goal here is to serve your company and their clients with your best work. She is standing in the way of doing that and is attempting to damage your career in the process.