This is heartbreaking news, though she had been ill for several years. She is the absolute master of contemporary fantasy for younger readers; her books have an entire shelf to themselves at my house. Her books are my go-to comfort reading; they are among my very favorite books, ever. Howl's Moving Castle, of course, is the source for the title of this blog.
Judith of Misrule, a dedicated Diana Wynne Jones reader, offers perhaps the best tribute, in the form of a quotation from one of Jones's books, The Magicians of Caprona:
For, as Paolo and Tonino Montana were told over and over again, a spell is the right words delivered in the right way.
Diana Wynne Jones made magic of one kind and another with her words, in all of her books. She will be missed, most greatly.