* J.K. Rowling: While her fortune likely came from the Harry Potter franchise, she also wrote other novels, making her a strong contender for the first billionaire novelist, regardless of gender.
* Danielle Steel: Steel has consistently been one of the best-selling authors in the world, and her estimated net worth has reached billions. While the timing of her achieving billionaire status is unclear, she is a prominent figure in the world of fiction and wealth.
* James Patterson: While not a woman, Patterson's prolific output and lucrative publishing deals put him in the billionaire category. This illustrates the difficulty in identifying the "first" as the path to wealth in publishing is complex and multi-faceted.
Ultimately, determining the "first" female billionaire novelist is challenging due to the lack of comprehensive historical data. However, the names listed above are strong contenders for the title, demonstrating the incredible success women have achieved in the world of literature.