I know that sometimes when professionals have arrangements to "cover" for each other, they are ethically not able to take the other professional's patients away from them. I had that happen with a dentist. So I would check with Marianne first to see if she is even able to take on as a regular patient, someone like you that she treated temporarily in an "on call" situation for your therapist. If she is not able to take you on because of that ethical concern, then you at least have learned what therapeutic approach is one that would work really well for you right now. And you could talk about this with Susan. She might be able to refer you to someone else with the qualities in Marianne that work well for you.

Hope it went well and that the concern I mentioned is not an issue here.