I'm mad at my coworker
What did she do?
She has badly insulted me several times, always denying she's doing anything wrong
Your best course of action is to ignore her and report her to your higher ups. You shouldn't have to deal with that at work.
I'm going to report her, she should be fired and I want my peace of mind at my job back.
You are doing the right thing, you deserve to do your job with peace and security. Your mental state with thank you, because you are staying there for nearly the whole day each day.