My D's is nine but loved the whole Rick Riordan collections, Percy Jackson, Heroes of Olympus, Kane Chronicles, Magnus Chase and his books on the Greek Gods and Greek Heroes. They should keep your dd going for a good while!
After finishing reading Rick Riordan's books we moved onto Peter Lerangis Seven Wonders series. They were fun and similar to the Rick Riordan books.
We have also read the whole Harry Potter collection, including the hogwarts library editions which were a fun quick read.
Our new favourite author is Cornelia Funke, we are currently reading the Ink Heart trilogy which is like a song to a literary lovers heart! Both of my DC are loving me reading this series aloud. On this years reading list we have added Funke's Fearless, Reckless, Ghost Knight and Dragon Rider books.
After that we will be moving onto Neil Gamain's Stardust (yay!!) and Never Where books.
Another vote for Sophie's World, it was my favourite book as a teenager (philosophy based and no sex/ violence).
Definitely don't let her read flowers in the attic!
Judy Blame Are you there God was one of my favourites at your daughters age. I also read the whole Babysitters Club and Sweet Valley High collections. I was a few years younger that your DD when I read Little Women and Secret Garden although I loved them both! I also loved Jane Austin books although I was fifteen when I read most of them! I loved the James Herriot books too, which reminds me to add them to our reading list for this year!
I'm almost jealous of the choice of books available to kids these days! I lived my youth with my head thoroughly engrossed in series after series of books!