3.5 stars, really.
As in the first book, Kowal's strengths lie in the world-building, offering a more accessible window into Jane Austen's playground. This sequel expands its reach to give a glimpse of Europe, though, something Austen did only by proxy.
The continuing adventures of Jane and her loved ones take her to Belgium for her honeymoon, where she learns more about both glamour and married life. The possible reentry of Napoleon into France brings intrigue and peril to the locals, causing Jane to take extreme measures to "save the day."
I liked this book better than the first one--it's a bigger story, with more of a plot and higher stakes. So good job on that. Its weaknesses continue to be an overreliance on Austen stories for mannerisms/plot points and the fact that Jane is more than a bit of a Mary Sue.
If you have a friend who's intimidated by Jane Austen, Kowal is a worthy alternative.