As Margaret's purpose is my focus I pay particular attention to any scene that she is in. There is a quote that Marianne makes later to explain doing impulsive things if it's alright for me to jump ahead to Ch. 13 for a moment: "...if there had been any real impropriety in what I did, I should have been sensible of it at the time, for we always know when we are acting wrong and with such a conviction I should have had no pleasure." While Marianne is referring to a different incident at the time, I think this is her basic philosophy about such things. She is obviously taking great pleasure in this activity with Margaret so obviously, to her, their can be nothing really wrong in it. I have to say, though, that I do enjoy this scene. I love experiencing this little adventure with them. There is a feeling of being carefree and free-spirited about it that is appropriate to the setting and the moment that I like, a bit of sneaky fun that, though not permitted, is basically harmless and would not ruin any reputations if they'd been caught doing it. One of the things this scene shows among others which I will put in a separate post is that in many ways Marianne is actually closer to Margaret than Elinor. I agree about your conclusion that Margaret is necessary to make Marianne a middle child to show Marianne in transition from childhood to young lady... I think Margaret is necessary in this particular scene because together she and Marianne get so tied up in the enjoyment of the moment, they don't notice the clouds have united over their heads. If Marianne had been alone, she would likely have turned back sooner (and I certainly couldn't imagine JA having Marianne carrying on by herself as she does in this moment with Margaret) and thus she would not have had to run, thereby falling and turning her ankle...and alas, no dashing Willoughby to rescue her.... I suppose in actuality, she could have turned her ankle while simply walking down the hill by herself to get home before the rain, but it would have lacked the build up of the drama and tension of the girls doing something they shouldn't be doing which is preventing them from paying attention to the skies, the driving rain they get caught in, the scramble to get out of it and so on... :)