Reading it again, I am of course favourably impressed. Austen set herself a difficult challenge in making Fanny her heroine--Fanny who, even in her late teens, is too easily embarrassed and rendered speechless, too easily intimidated, too easily reduced to blushes which are themselves ambiguous and sometimes lead to further confusion. Why doesn't she speak for herself more, as other Austen heroines do? Why is she such a wet blanket? No wonder the people around her (in general) don't think highly of her; as an American might say, you can't expect other people to sell you if you don't sell yourself.
In the other novels it is mainly the heroine who makes a great mistake, nearly misses her chance at a successful and happy marriage, and then repents her mistake and arrives at a happy ending. There is a gain in self-knowledge. In Mansfield Park, I'm beginning to think Fanny is the other character who never makes a mistake. Even when her blushing silences cause awkwardness and confusion, it is not clear this is her fault in the way that actively bad words and deeds would be. Edmund, her cousin who begins as more of a brother, is the one who has to learn.
Then there is Austen. Maybe she thought Fanny was one kind of female that Jane herself might have been--if she hadn't been so intelligent, and if she hadn't had at least a little of the sauciness of Elizabeth Bennett in Pride and Prejudice. Austen the tough-minded writer lets us see Fanny's and her own judgment of Fanny's parents:
On her father, her confidence had not been sanguine, but he was more negligent of his family, his habits were worse, and his manners coarser, than she had been prepared for. He did not want abilities; but he had no curiosity, and no information beyond his profession; he read only the newspaper and the navy-list; he talked only of the dock-yard, the harbour, Spithead, and the Motherbank; he swore and he drank,he was dirty and gross.
She might scruple [unlike Austen] to make use of the words, but she must and did feel that her mother was a partial, ill-judging parent, a dawdle, a slattern, who neither taught nor restrained her children, whose house was the scene of mismanagement and discomfort from beginning to end, and who had no talent, no conversation, no affection toward herself ....
UPDATE: I think Austen comes close to suggesting here that, almost in terms that Hobbes and Hegel would recognize, slaves see more clearly than masters. Masters are too busy enjoying being masters, their vision clouded by pride and self-indulgence; only those who have been continually frustrated have enough "outsider's" perspective, just on the outside looking in, to see both others and themselves more clearly. Obviously there is more to say: Fanny is not exactly a slave--she is a second-class family member living among the gentry, not really required to do much menial work or exert herself. A true slave might have no opportunity to think at all. Frustration and suffering perhaps best those who feel most. But Austen seems to suggest some moral truths are more available to those who suffer. Edmund remains a bit deluded about Mary, no matter what she says or does.
Almost in the last lines of the novel, Sir Thomas seems to reflect that of all the people in his little world, those who suffered early or, as in his older son's case, to a significant degree, turned out best.
...in the general well-doing and success of the ... members of the family, all assisting to advance each other, and doing credit to his countenance and aid, Sir Thomas saw repeated, and for ever repeated reason to rejoice in what he had done for them all, and acknowledge the advantages of early hardship and discipline, and the consciousness of being born to struggle and endure.
Those who are most indulged in their youth turn out worst: Maria, out of all Sir Thomas's children, Mary and Henry Crawford, young Tom Bertram before his brush with death. They are the leaders of the famous play, which perhaps really was immoral, and in any case really did lead to disastrous consequences, just as a certain kind of moralist might wish. Preparing the play allowed them all to exercise their whims, and vent their complaints (mainly to Fanny, who knew all and saw all) at any frustration in doing so. Edmund held out for a while, but then joined in, to the triumph of the others. After all, wasn't he a son of Sir Thomas?
Of course the idea that the theatre encourages immorality is quite old-fashioned--there has been so much water under the bridge in recent decades. Strangers uttering the words of love, with as much conviction as possible, might break the hearts (and vows, including marriages) of others, and might suffer themselves. Isn't that what hooking up is all about?
Austen wrote in what now seems the early stages of the Napoleonic Wars. The navy was a force to reckon with, even in the country houses on which she focuses. Admirals and captains were making fortunes, and rising in society in a way that was still largely controlled by the gentry. Who was going to win the world, rule India, and so on? The spoiled children of the gentry, or someone else? Austen was making herself, almost prospectively, the poet of the new Victorian middle-class, prosperous, hopeful about the future, and highly moralistic about sexuality and the family--partly because they want sex to remain very romantic, and true to the feelings of good people.
Fanny's rude father, a one-time lieutenant of marines, in some ways hopeless, reads about the adultery involving Maria in the newspaper--surely a middle-class invention--and condemns such wrong-doing. Fanny and Austen both clearly think he is right--even living as he does, he can properly condemn the immorality of the gentry, and treat them as if they otherwise don't count for much--their day is passing.
FINAL UPDATE: Once her younger sister Susan comes along, Fanny is enough justice to admit that Susan has the potential to be a better all-round person than Fanny herself. When we first meet Susan she is "back home" in Portsmouth, with Fanny's rough and rude family, and Susan is getting a reputation for being a bossy scold. Fanny sees that Susan is often right on the merits of an issue, but she doesn't seem to realize that in many cases, speaking out will not improve the situation, and in fact will make things harder for herself. Susan has great potential:
Susan saw that much was wrong at home, and wanted to set it right ... Fanny soon became more disposed to admire the natural light of the mind which could so early distinguish justly, than to censure severely the faults of conduct to which it led. Susan was only acting on the same truths, and pursuing the same system, which her own judgment acknowledged, but which her more supine and yielding temper would have shrunk from asserting. Susan tried to be useful, where she could only have gone away and cried; and that Susan was useful [at age 14] she could perceive ....
Later Susan takes over Fanny's former role as house comforter in Mansfield Park, and probably does a better job of it:
Her more fearless disposition and happier nerves made everything easy to her there. With quickness in understanding the tempers of those she had to deal with, and no natural timidity to restrain any consequent wishes, she was soon welcome and useful to all; and after Fanny's removal [she became], perhaps, the most beloved of the two.
Even Fanny seems to admit that she is a bit too much of a cry-baby to do as much good as she should. So why did Austen make her this way? I thing harsh truths are literally forced upon Fanny by her timidity. Even decent people learn they can get away with things with her--being late for appointments, leaving her in an uncomfortable spot, simply refusing to consult her as to what she wants. She sees how nasty they all are--eventually she tries to tell Edmund, but he doesn't really believe her. The same people are so nice to him. One might think Fanny would escape into a fantasy world where she is queen, but this never happens. She is as free from delusion about herself as she is about everyone else; perhaps Susan, as a more successful person, is also at least a bit more deluded about what the world is actually like?