There's no definite answer as to whether it's a best - seller. It could be that the story really resonates with a large number of readers and quickly climbs the best - seller lists. On the other hand, it might not gain as much traction as expected. Maybe the plot or characters didn't quite capture the public's attention as much as her previous works. Without proper data on sales and popularity over time, it's hard to say for sure.
To know if it's a best - seller, we would need to look at sales figures and rankings. Just because it's her latest novel doesn't necessarily mean it will be an instant best - seller. However, given her popularity as an author, it has a good chance. But it also has to compete with other popular novels in the same genre at the time of its release.