I Capture the Castle is the journal of the 17-year-old Cassandra Mortmain, who lives in genteel poverty in a ruined castle in Suffolk in 1934 with her novelist father, stepmother, and her beautiful sister Rose. The family is supported by their deceased maid's son, Stephen, who works at a neighboring farm and is in love with Cassandra. They also live off the meager, declining royalties of Thomas' only novel and whatever his wife Topaz can borrow when she is in London modeling for artists. When two American brothers inherit the manor that their castle belongs to, a Pride and Prejudice-like plot is put into motion (which Smith humorously acknowledges by having Rose exclaim, "Netherfield Park is let at last" upon hearing the news.) I read this during my Harry Potter phase because it is one of J.K. Rowling's favorite books, and it became one of my favorites too. I saw the play last month at the Shakespeare Theatre of New Jersey, and it was just as good as the book. Unforunately I got the idea from the theater program that the play is usually only performed in England, where it has been popular since its debut in 1954.
If you loved Rebecca by Daphne du Maurier, it is the same type of romantic English tale, except Cassandra is a more independent, free-spirited (and extremely well-read) main character. LibraryThing also suggests Cold Comfort Farm by Stella Gibbons, Miss Pettigrew Lives for a Day by Winifred Watson; Emma by Jane Austen; and North and South by Elizabeth Gaskell among other similar recommendations.