I think Fanny is too good. She has good judgement, always, good manners, good looks, the approval of all who meet her and her "adoptive family". The biggest problem she confronts is the attention of a handsome, rich, bad boy who tries to reform in order to marry her. Her Aunt Norris is difficult, but easily ignored. Her bad cousins are self destructive, but don't torment Fanny. Although she likes to think of her self as Cinderella, it's a false construction. Her parent's home, which she left at age 10, is loud, disorganized and dirty. Though she pines for "home" for eight years before returning, it doesn't take five minutes for Fanny to realize that her move to Mansfield Park was the best thing that ever happened to her. Her mother is a dolt and her father has no interest in her or any of the females in his house. Mr. Crawford, the bad boy, is better able to accept her lower class parents than she is.
Jane Austen is a great writer, but for me, Mansfield Park is not as sharp nor as funny as her other works. I hate to write this, but I preferred the movie which was based on the novel. It was so good that I decided to read the book. Go figure.