JK Rowling has had 7 book adaptions, the 7 Harry Potter books, one of them just happened to be split into two films. And fantastic beasts and where to find them was not an adaption, those were written as scripts and therefore weren't adapted from a book.
Twilight (2008), The Twilight Saga: New Moon (2009), The Twilight Saga: Eclipse (2010), The Twilight Saga: Breaking Dawn – Part 1 (2011), The Twilight Saga: Breaking Dawn – Part 2 (2012), The Host (2013).
JK Rowling has had 7 book adaptions, the 7 Harry Potter books, one of them just happened to be split into two films. And fantastic beasts and where to find them was not an adaption, those were written as scripts and therefore weren't adapted from a book.
Tom Clancy? (6)
Charles Dickens (40, including several remakes)
Louis L'Amour (16)
Elmore Leonard (29)
What a cr*ptastic list