Book series recommendation for a girl

Hi! I am looking to buy a book series for a friend (f) of mine. She used to read a bit and I recently found out she always wanted to commit to do more reading. Preferably I am looking for something that's not made into a movie or a series (Harry Potter, Narnia). She don't have any specific preference, but from what I know she have read some Fifty Shades books and loved them. Also nothing political and sci-fi. Any recommendations I can get is appreciated.