Potent indeed Barbara! (:D) I agree Marianne feeds and encourages her grief just as she and her mother did after the death of Henry Dashwood. Although her grief is from a different source the excess sensibilities is nearly an instant replay of the past. It is strange the expression of such strong feelings is actually so lacking in spontaneity. I have to wonder how much Marianne and Mrs. Dashwood have trained themselves to respond to grief in this manner. Did they grieve great-uncle Dashwood in a like manner? Further, in Ch. 8 Marianne found Elinor and Edward’s behavior towards each other at Norland incomprehensible, especially their farewell:

"And Elinor, in quitting Norland and Edward, cried not as I did. Even now her self-command is invariable. When is she dejected or melancholy? When does she try to avoid society, or appear restless and dissatisfied in it?" (Ch. 8)