We could even suggest waiting until all seven are out and she's all done with them, but no one knows how long that will be. She was doing 1 a year until after book 4 came out. She took time to have a hand in the first two movies (and the third is in production), got married, had a second kid with the new (younger!) husband, released two smaller books in early 2001 for charity....
But she's supposed to start on #6 this summer, after the hype for 5 starts to fade.