Educate her on how therapy helps. Lot of people think that therapists are mind refers and give advice and change the person you are. Also her perception maybe influenced by media which portrays psychologists or patients as crazy which is really u fortunate. Expln to her that a therapist listens unconditionally, and uses scientific methods to find the root cause of anxiety or any concerns and work towards resolving problems by simply helping your reflect and facilitate your growth by training you with various coping mechanisms. There is no mind reading. She has the freewill to talk about what she wants in the session. Of course the goal is to honest for your betterment which will happen once the therapeutic relationship strengthens. She will basically learn to identify her own challenges, be more self aware, learn to regulate her emotions better and lead a happier or healthier life. Maybe you can share good YouTube videos or articles on busting myths on mental health and what happens in psychotherapy or counselling. Also explain the difference between psychologist, clinical psychologist, psychiatrist, counselling psychology or counsellor, psychotherapist and life coach. You will get all this info online.