There have been many, many books written about the Holocaust and it would seem that every possible story has been told. However, I learned a lot of things I never knew in the Secret Holocaust Diaries and it was really interesting to see the war and the Holocaust through a Russian citizen's eyes - a perspective that is not as common among the existing literature.
Nonna's diaries were published only after her death and her friends and surviving family helped pull the diverse papers together and organize them into a book. I think that is the book's major weakness. Nonna's diary entries are poignant and well written - however the impact of her words are undermined and watered down by the frequent asides and factual interjections from those editing her story together. If the diaries had been allowed to stand on their own I think the book would be much, much stronger.
For example, when mentioning that Nonna tends to interchange several names for her relatives and may have been confused about their names that adds nothing to the story. Just pick a consistent name and use it. Again with the back story interjected throughout, that would be much, much better as an addendum at the end of the book rather than scattered throughout. The extensive family history that is shared in various places is also unnecessary and doesn't add to the larger story - those things that contribute to the main story of Nonna's life should have been highlighted and other, irrelevant areas, saved for the family alone as that is who it is most relevant for.
When Nonna's words are allowed to stand on their own I think they are strong and impactful. With better editing and some careful revision this book would definitely get a four star rating from me - right now the structural issues are just too distracting.