"I see the disclaimer buried at the back of the book."
Considering the postscript contains dozens of spoilers, it would ruin the book to put it into the front. I much prefer the detail of specifically sorting fact from fiction in the postscript versus a vague, generic disclaimer in the beginning.
"She just looked in the Salem Archives at the University of VA and picked a cool name, without caring or even considering that this woman left descendants."
What does leaving descendants have to do with it? It's fiction and you didn't even know the woman! Not all historical fictions have to be completely factual. Maybe she did just pick a cool name because maybe that's all she wanted to take from the factual history of the individual. So what? That is her choice as an author and there's nothing wrong with it, whether the character has descendants or not. You don't own the memory or history of Deliverance Dane just because you're descended from her.
"Deliverance Dane's maiden name was Hazeltine."
And how do you know the author wasn't aware of this but simply felt it wasn't relevant to the story? Again, she has the right to take from history whatever she chooses. She does not have to prove her research by forcing meaningless facts into the story - I hate when authors do that.
"I am descended from her brother, so in addition to being an aunt by marriage (to Nathanial Dane, son of Francis Dane, whose daugther Abigail Dane Faulkner I am descended from) she's also an aunt by blood."
Thanks for sharing but I'm not sure why you felt it necessary. You come across as someone who is just trying to brag about his heritage with a very self righteous and possessive attitude. I especially don't understand your claim of slander when the book actually portrays Deliverance Dane as a good person. While she may have been "guilty" of the fictional idea of witchcraft, she was not guilty of using it to harm anyone.
"Now let's turns to the "facts" surrounding K.Howe's "descent" from Elizabeth Howe. In the same postcript you cite, K. Howe carefully does NOT claim that she is descended from Elizabeth Howe. Instead, she curiously says she is "connected" to her-not a recognized genealogical term. Her alleged "descent" from Elizabeth Howe is a selling point for her book."
None of this has to do with your original complaint that there should be a disclaimer, warning people that not everything about the characters are factual. Which is indeed already in the book but you can't just concede to your error, you have to complain about the placement! For a lawyer, you really have come up with the weakest complaint and argument I've ever seen, purely to brag about and stake an ownership on your ancestry.