Final answer:
Legally, the therapist must respect Kathy's decision and discontinue treatment.
Step-by-step explanation:
In this scenario, the therapist must respect Kathy's decision and discontinue treatment. Legally, the choice to continue or discontinue treatment lies with the patient. Even if Kathy's mother and physician feel the therapy is beneficial, the therapist must honor Kathy's wishes. It is important to respect a patient's autonomy and right to make decisions regarding their own healthcare.