In addition to winning RG, Francesca appeared in the next year's final, so...give her credit for more than a fluke. She was no fluke. You know, I don't consider Ana's win a fluke either, since she had been in the previous final. However her no. 1 status was a gift of Justine Henin, and Ana did not handle it well perhaps because it was a gift.
Obviously, as noted, Sveta has more than one slam.
Petra is very young gamewise. Plenty of time to win another slam. Same with Vika.
Na is older, but I still wouldn't be surprised if she won another slam.