I own many books about the Salem Witchcraft trials, and have enjoyed seeing many of the original documents scanned online. My husband and I both have ancestors who were involved in the witchcraft trials.
I personally enjoyed the book you are talking about. It was a nice bit of fiction that was engaging and might encourage someone to look deeper into the historical record to find out what did happen.
I think that getting offended about the portrayals of our historical ancestors is a waste of energy. Besides, it is all a matter of perspective. For instance, I am a direct decedent of King Edward II of England. Does this mean that the movie Braveheart (in which King Edward is the villain)offend me? Not at all. Why? Well, from the perspective of the Scots, he was a villain. Never mind all the other things he did in his life that might make one see him in a different light. Besides, I could name a dozen inaccuracies in the film to boot, but that does not make it a bad film, just Historical Fiction.
Historical Fiction is a fun way to contemplate what it might be like to live in various places and times, and through certain events. But we must always remember that it is fiction.
We don't own the past. We can't say that we have ownership any particular part or person.