This is why so many people find it dodgy to sprinkle historical fact with fiction. From the views expressed by this author in this essay
"Hence my surprise at finding that in the Lunenburg case, white men in several instances ran enormous risks to uphold the rule of law."
"Does it seem plausible that an illiterate, twenty-three-year-old washer and ironer could stand up in a packed courtroom and conduct herself like a seasoned trial attorney? Nope, but it happened in Lunenburg, as did many other transcendent events. What a waste, should they be dismissed as fiction."
It's pretty obvious that had she not decided to be rigorous with the facts we would have had yet another "Whitey keepin' the poh ignernt black man down, shouldn't we all be ashamed of our skin color now" book. Instead she seems to have produced a piece of work that might actually give insight to the time period.
There's nothing wrong with historical fiction as long as it is billed as such. Often it is not. Even in straight history books it is seen as acceptable to include made up details for flavor. Well, as we well know, the devil is in the details. If the goal of history is to present information about the past for analysis and knowledge then maintaining a solid distance from fiction, even in the details, should be the overriding goal. Of course, as someone would be quick to point out, all history is biased. The effect of that bias should be lessened as much as possible and avoiding fiction at all costs is one good technique.