T's pretty much have to go "with the flow" If she were anti, you'd get in a "will struggle" and not make any progress. It's all always completely up to you, what your behavior is and what you decide to work on as far as symptoms. The symptom that brought me into 18 years of therapy with my T we never/rarely discussed! But, it got "cured" with the actual problems we did work on. Cutting isn't your mental health problem, whatever is triggering it is and that's probably what she wants to work on with you.

It's interesting to me that you wonder if she believes you or not, as if that's "important" to you (that she believe what you say and you don't accept that you will be believed as a given); I think you should discuss that with her.