One of the better critical reviews of The Casual Vacancy
What's unusual about Rowling's genre-skipping is that she has moved from children's author to adult novelist, rather than the other way around. Traditionally, that is a difficult feat. For example, Lucy Maud Montgomery, who published Anne of Green Gables in 1908, never achieved the same success with her long since-forgotten adult novels.
Applying the skills and experience you have acquired in other literary forms to children's books seems to make for a happier genre-changing transition. C.S. Lewis was an Oxford don, a medieval scholar and a poet when he began writing The Lion, the Witch and the Wardrobe, the first of the seven volumes in his Narnia series. A classic Christian allegory - although he denied that - the Narnia books have enthralled children and their parents for decades.
Most writers want to experiment with technical and literary challenges, to test their mettle, to find new audiences, to have fun with voice and narrative, to force themselves to keep staring at the blank screen. Even those, like the late Christopher Hitchens, who can't escape their own genre (his genius was as a polemicist and literary and cultural critic) admired the best writers for children. In a Vanity Fair column in October, 2002, he wrote about Philip Pullman, another writer who sticks to his main strength, decreeing that Pullman's books, especially the His Dark Materials trilogy (The Golden Compass, The Subtle Knife and The Amber Spyglass), "have begun to dissolve the frontier between adult and juvenile fiction." Hitchens and Pullman shared a world view - they were both atheists, although Pullman likes to call himself an "agnostic atheist" - but Hitchens's point about the artificial boundary separating books for children and those for adults is well taken and speaks to the Harry Potter phenomenon.
Sandra Martin, a senior features writer at The Globe and Mail