Marianne truly loves her sister Elinor and is humbled by her and her behavior. Marianne sees, really sees, by contrasting her own behavior with Elinor's behavior, that there is an alternative to drama. Drama queen - yes, particularly at first! That's why she and Willoughby seemed to fit each other so well. But Willoughby exposes in his "confession" to Elinor the fact that he does not repent and grow from his experience.

Marianne, as you mention, is not really looking for an audience. I think Willoughby has (that's why he seeks Elinor out after he's found out that Marianne will live.) But again, Marianne sees, through Elinor, that there is a different way - that one can be very sad or very happy even without the drama - without showing it. Marianne will always be more dramatic than Elinor. But she sees that she may harm the people she loves by glorifying and being immoderate in the downs in life. But both Marianne and Willoughby (and Mrs. Dashwood, too!) hold charm because of much of their drama. But with some moderation (which is found by observing someone like Elinor) death scenes can be escaped. And also without the artificial acting out of drama, Marianne realized with Elinor that drama can still exist! When aware of it, Elinor's suffering while knowing of Lucy's engagement to Edward is just as dramatic.