I predicted this:
http://www.abc.net.au/news/4819470
I ever went as far as trawling thru the Little,Brown author list for likely suspects. Didn't expect it to be an adult crime novel.
Here's the question: she's now written three lengthy adult novels within a relatively short time frame. It begs the question how many other novels she has slipped under the radar during that lull after the last HP was published. My money is on at least one other work under a different name.