The arrival of Aunt Shaw reminds us of many of Margaret's original prejudices about Milton and its inhabitants; she finds the town- and the workers- grimy and vulgar, disapproving of the lower classes' free and easy way of talking to whomever they please, however they please. Aunt Shaw is no more approving of Milton's upper class, the nouveau riche, since their elevation has been due to trade, and- in Mrs. Shaw's opinion- money can't buy gentility. As we can recall about Margaret's first weeks in Milton, she originally shared some of these opinions, being genuinely startled when strangers in the street spoke to her, and sometimes offended by the manners and speech of the Thorntons, or Nicholas Higgins. Now however, she is used to- and approves of- the opportunities afforded by industry for people to change their financial and social positions. Also, in a town where the lines between the classes are blurred and flexible, Margaret enjoys friendships with people all over the social spectrum, something her aunt would find unthinkable.
As Margaret regains her strength, we see her begin to push back a little against her aunt's well-meaning but smothering cosseting. She insists on going through her father's books, and then on going to take her leave of the Higgins and Thorntons. Though Margaret gives in to Aunt Shaw's insistence on accompanying her- and travelling in a carriage- there are hints that Margaret is soon going to tire of being overly protected and chaperoned. Over the last couple of years, she has become accustomed to a good deal of independence: for instance, in Milton she generally walks- unaccompanied- wherever she's going without giving it a second thought. It is likely that she will find it unpleasantly restricting to return to London's much more rigid strictures for young women. In addition, due to her mother's illness Margaret was to all intents and purposes de facto mistress of the Hales' house. It will not be easy for her to go back to her Aunt's home and be treated once again as a young girl who must be taken care of.
Margaret's apology to Mrs. Thornton shows us once again how much she has changed over the past couple of years. Previously, it is unlikely that Margaret would have been able to bring herself to do so, after having been unjustly accused and chastised by the blunt-spoken woman. But Margaret's pride has been humbled by the knowledge of her own failings and, conscious of her own need of forgiveness, she is quicker to extend it to others. There is, on the other hand, no discernible lessening in Mrs. Thornton's pride but she does soften towards Margaret and accept her apology, sensing the girl's distressed sincerity. It's true that the fact that Margaret is being removed as a temptation and torment for John contributes to Mrs. Thornton's kindlier attitude, but she is also genuinely touched by Margaret's very obvious grief. Even in her angriest moments, Mrs. Thornton has admired Margaret's indomitable spirit (so lacking in her own daughter) and she is rather shocked- and moved- to see that spirit so crushed.
Nicholas Higgins comes to see Margaret before she leaves the following day, which is a comfort to her. He had been waiting until she was well to come, but Thornton told him that she was leaving the following day... for someone who is supposedly indifferent, John certainly manages to keep helping Margaret in small but important ways. She and Nicholas talk of her father and Margaret gives him Mr. Hale's Bible. That he emotionally accepts it shows how much he, too, has changed; he is a much different man from the one who angrily rejected Bessy's talk of God's love.
When Margaret gives him money to help with the expense of the Boucher children, Nicholas tries to refuse it, saying that money shouldn't pass between friends. This too shows how much their relationship has changed. When they first met, Margaret regarded Nicholas as Bessy's angry, rude, and sometimes drunk father, to be endured for her sake. Nicholas, for his part, considered Margaret to be a pious miss, and was frequently bitter and sarcastic in his statements to her. Both of them have changed, and Nicholas has lost some of his sharp edges. United through shared grief and common purpose (caring for Boucher's children) the two of them have become fast, if unlikely, friends.