It may be legitimate of you to say, but it isn't very wise. Of course if the therapist "can't" give you the time it's because there are priorities over you. Her mother's chemo appointment, another client's long-standing appointment, choir practice, her kid's ballet lessons. How arrogant would it be to feel she should stop her whole world for you? What should make you her top priority in life, no matter how good a therapist and no matter how much she takes care of you, her other life should end?