Final answer:
A Humanistic psychologist would be most useful to Gwen, as this approach focuses on individual growth potential and the pursuit of self-actualization.
Step-by-step explanation:
If Gwen is in search of the deeper meaning of her life and would like to learn more about her potential as a human being, the type of psychologist that would likely be most useful to her is a Humanistic psychologist. Humanistic psychology, with figures such as Abraham Maslow and Carl Rogers, is centered on the growth potential of individuals. It asserts that people are driven by an intrinsic desire to achieve self-actualization, focusing on the quest to become the best person they can be. This approach emphasizes free will, self-determination, and the striving for personal growth and fulfillment.