I love the books and all, but honestly, i would not want her to write anymore. As much as i miss having these books and movies around, i would not want more to be written, it would just feel like she's milking the series, and it would just feel awkward. It ended exactly where it needed to, it tied up all loose ends, everything got resolved, and what is there to reveal in the next one? And if we want to know what goes on in his life afterwards, just have Rowling write a paragraph explaining what happens, nothing exciting would happen, and one about his kids would be boring as there is no longer any Voldemort around to watch after, and i would not want a new series of some bad guy taking over to start up, again, it would just feel in-genuine and milked.