L. M. Montgomery's Anne of Green Gables
My very favorite book in middle school. Set in 1890's Canada, this tale of an orphan who gets herself into all sorts of scrapes because of her adventuresome spirit, this is not a book everyone likes. Still, girls who like historical fiction, girls who are quiet, introspective, smart and a little different from their peers, and girls who are fans of Alcott will be served well by this book. I have two students reading this now (I handed it to one after she enjoyed A Tree Grows in Brooklyn!) -- I do a little happy dance whenever anyone checks this book out.
More accessible to a larger audience, Julie Andrews Edwards' (yes, the actress) book Mandy is a book that is absolutely wonderful, but no one can explain why.
Mandy ( and there are better covers available) is an orphan in an English orphange, finds a cottage in the woods that she cares for, and eventually finds a family to love. I have a student who checks this book out twice a year just to reread it. I was given a copy of this in 1974 for Christmas!
When girls check out Maud Hart Lovelace's Heaven to Betsy, I tell them if it compels them to make fudge, they have to bring me some. Set in the 1890's in Minnesota, I loved the depiction of family and school life at the time. Different from today's life, and yet oddly similar, I read these in high school, mainly in the orchestra pit when I was in musicals, and often did have to make fudge, because Betsy does so often. There is a series of these, and even a Lovelace fan club. Originally published in the 1950s, these can be hard to find.