I think that a very careful understanding of the patient's goals, plan, insights and likely tests has taken precedence over a diagnosis for me. I use the plan concept much more than trying to pin down what category the patient would fit in. I do agree that one must have a way to organize how you are going to help the patient.
I try to understand what are the underlying pathogenic beliefs that are interfering with the patient accomplishing his or in this case her goals. I do see Kathy as depressed but that is not as useful to me as understanding that she has held herself back for unconscious reasons, from enjoying her life.
The most effective approach for treatment form a Control Mastery perspective is one that will identify Kathy's beliefs and clarify and disconfirm them. Each treatment is unique. This is a very case specific theory. The individual treatment plan will depend on the patient's specific history, fantasies, constitution, capacity for insight, style of testing and unconscious beliefs.