I'm curious to know where the author acquired this information: "Sarah, who aspired all her life to be a French actress, maintained a mysterious identity. . . . It was said she spoke fluent French but “broken” English." After all, she was born in Connecticut!
I read some of the sample pages.
As for being "historical - fiction", it seems much more fiction than historical.
The author claims otherwise. "The book is historical fiction, but according to O’Connor, mostly true. And in keeping with all his other Civil War novels, the book is narrated by Mrs. Slater herself, in first person."