Clocking in at 4 books each, I have Jean Craighead George, who was the author that inspired me to study ecology (if only I’d realized it at the time) , and J. R. R. Tolkien. I’m missing The Two Towers, though.
With 5 books each I have James Herriot and Kristen Britain.
With 6 books I have Eva Ibbotson, some of both her children’s and her young adult/adult works.
With 7 books each I have Madelaine L’Engle and Elizabeth Moon.
With 10 books each I have J. K. Rowling and Mercedes Lackey. I have British editions of the Harry Potter series, plus the US edition of the first book (for some reason), Beedle the Bard, and Quidditch Through the Ages. If this were my parents house, we’d have way more Mercedes Lackey than this…
With 31 books I have Brian Jacques. Wow, this one surprised me, but I have all of the Redwall books, including the cookbook, plus The Ribbajack. It adds up!
It’s interesting to see how this does and does not line up with my favorite authors.