For me, one label comes to mind when regading Mrs. Ferrars:

"BATTLE AXE." That one is all over her.

Another barbed arrow from the pen of Miss Austen on Mrs. Ferrars from Ch 50:

"....It was as much, however, as was desired, and more than was expected by Edward and Elinor; and Mrs. Ferrars herself, by her shuffling excuses, seemed the only person surprised at her not giving more."

With Mrs. Ferrars, it is all about "appearances" and very little about "substance." And so it is with the genius of J.A. that she makes us the "fly on the wall" in exposing the selfish motives of Mrs. Ferrars.....someone who isn't happy until she makes those closest to her miserable by suffering her ill will.