The calm and polite unconcern of Lady Middleton on the occasion was a happy relief to Elinor’s spirits, oppressed as they often were by the clamorous kindness of the others. It was a great comfort to her to be sure of exciting no interest in one person at least among their circle of friends: a great comfort to know that there was one who would meet her without feeling any curiosity after particulars, or any anxiety for her sister’s health.
Lady Middleton, described this way, reminds me of Lady Bertram in "Mansfield Park." No doubt Fanny Price could feel relaxed around Lady Bertram in the same way that Elinor experiences here with Lady Middleton