I think she should see the video where Lett so blatantly lies, specially if the subject of child abuse is fresh in her mind. Why read about and old lie, written long ago if you have a recent one? Specially if you compare that the book is a PDF you get online, against a video of their own channel? Not that the book is bad, but if you weight them both, which one is refutable and which one is not?
Also, you could just tell her what chapter to read, regarding the dfing of Ray Franz and then let her own curiosity drive her to read on her own.