I propose to delete jk-rowling, and not recreate it.
This tag is currently used on approximately 30 questions. All but two of those are also tagged harry-potter. The two remaining questions should be tagged with harry-potter too, because they ask about Rowling writing Harry Potter, even if they don't mention it explicitly.
Rowling had specifically said that her future writings outside the Harry Potter universe are unlikely to be in the fantasy genre. Her latest book, Casual Vacancy, is decidedly not in the fantasy genre. Thus, it is quite likely that this tag won't be necessary in the future either. This, and the fact that about 10% of our questions are related to Harry Potter makes my question different from my previous question Remove tag [my-little-pony] .