I still am having some trouble sorting out what it means that Louisa will make or break the relationship between
What I come down to is that they both have to alter some aspects of their behavior, but that Louisa needs to take the lead in verbalizing what she wants and needs from Martin and eliciting the same from him. Since left to his own devices what we have seen Martin do is either suffer in silence or explode, or make high-handed assumptions.
I believe your statement is accurate. It is Louisa we must rely on now because she is the closest to "normal" we've got. She must guide the Doc because he has no clue. Although she is not great at communicating by any means. She's good at getting offended & stomping away. Her insecurities.