@oralloy,
Her book claims that her uncle shouldn't have been the president-by which she means her cunning uncle, who's in cahoots with Putin along with the backing of Jeff Sessions and Steve Bannon, resorted to using underhanded tactics to defeat Hillary Clinton.
On top of that, she also charges that her uncle's record as a business man is also a dodgy one, despite Trump's claim to be a successful business icon.
Be frankly, I don't think the accusations made by the author in this book are going to dent Trump's efforts to bolster his conservative base. And it would be foolhardy for Biden to use this book as smoking gun to prove that Trump has been a con artist even in the eyes of his family members. Why? Because Trump and Fox News could simply dismiss it by saying that it's widely reported that the author of this book holds grudges against her uncle.
Trump and Fox News could also deflect attention by bringing up the fact that Biden subscribed to the 1994 Crime Bill and its mandatory minimum sentences and his 1977 comments about segregation again and again. Such damming accusations against Biden hurt Biden more than Trump's disgruntled niece's accusations against her vulpine uncle.
All in all, it's not the time for Biden and his advisers to whoop it up since the real battle hasn't even started it.