I wouldn't ask -but not just saying Fine as a response to a client asking seems like another power play on the part of the therapist.
Ways Therapists May Use Positional Power
Right to ask questions: Therapists’ roles give them the right to ask questions but not necessarily to answer questions. This discrepancy elevates therapists’ power compared to their clients.
Maintain anonymity: The fact that most therapists know much more about their clients than the reverse gives them a significant power advantage. “Unknown” therapists can easily become mysterious and powerful in the eyes of their clients....
Power in Psychotherapy and Counseling Including Issues of Undue Influence, offered by Zur Institute, Inc.