] (snip) while Elinor, though "deeply afflicted" is cast in the role (and equal to) struggling and asserting herself. This single paragraph is evidence enough for me that Elinor's strength is not new, her role in the family as "the strong one" is expected, a given. I admire her all the more for it, frankly.

Yes. I think Elinor's strength and her role as "mother" predate Dashwood's death. To some extent, they may be character traits, I think. Her outlook is more sober, her temperament less volatile, less given to romantic fancy than that of her mother and sister ~ which is not to say that she does not feel or care deeply; she's just not run away with by her feelings. But there is also an element of discipline in this: she does not allow herself to wallow in her emotions, good or bad. Like you, I respect and admire her for it.