In this chapter, we finally begin to see Marianne living up to the praise she received in Ch. 1. Among the things she would not have done in chapters 2 through 42 are:
1. Thanking the Col. for bringing her mother to Cleveland.
2. "taking so particular and lengthened a leave of Mrs. Jennings -- one so earnestly grateful, so full of respect and kind wishes as seemed due to her own heart from a secret acknowledgment of past inattention."
3. On the carriage ride home, turning her head to keep her crying to herself.
4. Showed she knew her limitations at the pianoforte, but avoided the wallowing self-pity.
The only thing that came through as the same Marianne was a possible over-reaction in the scope of her resolutions. She seems to want to eliminate every vestige of sensibility to lead a life of piety and sense. Still, she's making great strides towards becoming a more complete person.
Then comes "The Walk." The things that she and Elinor discuss during this walk probably deserve their own thread. For now, suffice it to say, any doubt that she truly has learned her lesson, disappear.