Final answer:
Dr. Goodwin should assess for a conflict of interest due to her past relationship with the client's spouse, disclose this to the client, and consider referral to another therapist to maintain ethical standards and client trust.
Step-by-step explanation:
When a therapist discovers they have a previous personal relationship with a client's spouse, as Dr. Goodwin does in this scenario, the ethical course of action is to consider the potential for a conflict of interest and the ability to maintain professionalism. Dr. Goodwin should assess whether this past relationship could affect her objectivity and effectiveness as a therapist.
Moreover, professional ethics and guidelines would likely mandate that Dr. Goodwin disclose this conflict of interest to the client and possibly refer her to another therapist, ensuring the client's wellbeing and trust in the therapeutic process are prioritized. This approach respects the confidentiality and objectivity required in the therapeutic relationship.