I see the disclaimer buried at the back of the book.
The statement that little is known of her is a lie. A lot is known about her, the author just didn't research her. 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. Deliverance Dane's maiden name was Hazeltine. 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.

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. All the book leafs and publicity say she's descended from her. She needs to explain her "connection" to E. Howe, but of course, she neer will because no one really cares.

But I agree with you. It's silly to argument with people who know nothing about the history of the Salem witch trials, don't seem to be interested in the truth and have no ancestors (they know of) who were involved in the disaster. Or, if they do have ancestors have no interest in honoring their memory.