How does the arrival of Margret's family in Milton effect Elizabeth Gaskell's beautiful story?

AU: Mrs Hale has passed away, Fredrick has left Milton and the consequences of his meeting at Outwood station are still in play. Mr Thornton has told Margret that any 'foolish passion' he had for her is entirely over and he has scarcely been to see Mr Hale since. In this version of events Margret and John haven't been to the great Exhibition, John has never met Margret's family.

Edith Lennox had never been a brave woman; she had no call to be. All her life was spent in secure surroundings; she had been trained to deal with almost any situation that could occur in the highest circles in London society. Many complimented her on her poise and gracefulness. She was a determined young woman, when she had set her mind to a task it was always achieved. She was not a fool but had never enjoyed the thrust of an academic argument; that was for her cousin Margaret, debating with her scholarly father.

Since her childhood she had never spent more than a summer away from her cousin. She had always longed for Margret when she went on her summer trips back to Hellstone. With almost two years apart and with the hardship that she knew her cousin to be enduring she decided that she would muster all the bravery she had and would venture into the wild and squalid North.

Like most of Edith's plans it had been decided in a flash and contemplation of the details was left aside. She was walking with Sheltow in the garden re-reading one of Margaret's letters when it dawned on her that she should make a trip to see her. She could maybe convince her selfish father to come back to the south, especially with Mrs Hales passing. Margaret could be saved and brought back home.

Edith knew very well that her husband and mother were not going to allow her to travel so far alone, she would need a chaperone. With Maxwell's business hours and her mother distaste for trade she doubted that they would acquiesce. It would be a different story with Henry, surely he would see that the trip would allow for him to see Margaret and perhaps Margaret feelings for Henry would have soften after being surrounded by the harsh manners of Northern tradesmen for two years. This could end very well indeed.