"That Lucy had certainly meant to deceive, to go off with a flourish of malice against him in her message by Thomas was perfectly clear to Elinor; and Edward himself now thoroughly enlightened on her character, had no scruple in believing her capable of the utmost meanness of wanton ill-nature."

I've always wanted to let Lucy have one upside the head for that. First, Lucy couldn't resist sending the news that she is now Mrs. Ferrars, knowing that Elinor will believe she's Mrs. Edward (not Robert) Ferrars. Though the truth will come out soon enough, it causes Elinor pain, as Lucy doubtless intended it should. And that smarmy letter to Edward . . . *shiver of disgust*