The story of Fanny starts with Mrs. Norris inviting her to live in Mansfield Park, because Fannys' mother just had another baby and with her no good husband her sister (Mrs. Norris) decided to help. But she herself couldn't suppost Fanny, instead she told her brother in law Sr. Thomas to keep her. He and his wife reluctantly agreed to help the girl. They had four of their own children Maria, Julia, Tom and Edmund. Fanny was treated as she was, poor and ignorant. Her cousins Maria and Julia made fun of her and never let her forget that she was below them. But Edmund took her under his wing and protected her. He made sure she was treated equal. That's the beginning, the rest pretty much covers how her life evolved at Mansfield Park, how from a poor young girl she grows up to be a civilized young lady. If your read Pride and Prejudice this might be a disappointment to you, it doesn't have the same suspense, you can pretty much guess the whole story from the beginning.
Ok so I'll be honest for the first half of the book I thought I was just going to give up on it. I couldn't get my head around all those characters. There was too much going on in the first few chapters. I felt like I just popped in unannounced and had to catch up to the story. And then once I did catch up on what was going on I didn't feel like Fannys story was important enough. Austen paced the book well, maybe too well. There was too much unimportant information between the important, interesting events.