What IS she supposed to do with Marianne? OK so she can't understand that M's grief is "too deep" for her to cheer herself up or to be amused by social events or cards, but even if she could, I can't quite see what she's supposed to do. She can't cure M's heartache, she can't bring Willoughby back to her. All she can suggest is that M cries herself out, and then tries to pull herself together and try and fidn some amusement for herself to take her mind off things for a bit.