I often thought of how Mary Musgrove turned out the way she did. Was it because she was in the middle, not as grand and important to her father as Elizabeth and certainly not as sweet and pleasant-natured as Anne? Every time I read “Persuasion” I cannot help but think of Mary, particularly as she is first introduced in chapter 5.

“Though better endowed than the elder sister, Mary had not Anne's understanding or temper. While well, and happy, and properly attended to, she had great good humour and excellent spirits; but any indisposition sunk her completely. She had no resources for solitude; and inheriting a considerable share of the Elliot self-importance, was very prone to add to every other distress that of fancying herself neglected and ill-used. In person, she was inferior to both sisters, and had, even in her bloom, only reached the dignity of being "a fine girl." She was now lying on the faded sofa of the pretty little drawing-room, the once elegant furniture of which had been gradually growing shabby, under the influence of four summers and two children; and, on Anne's appearing, greeted her with --

"So, you are come at last! I began to think I should never see you. I am so ill I can hardly speak. I have not seen a creature the whole morning!"
I could never make up my mind whether I like Mary or not, though she is certainly to be preferred over Elizabeth. My question has always been could Mary have become a more reasonable person, without this constant need to complain of ill-usage and fancying herself ill if Lady Elliot had not died? Perhaps, if Sir Walter had not been so absorbed in himself and Elizabeth, Mary would have become as amiable and understanding as her sister Anne?
This scene of Anne’s arrival in the upercross cottage has always made me smile. Mary may be vain, silly and rather fussy, but I think she at least makes Anne feel necessary, unlike her father and Elizabeth.