I’m old (38) and I haven’t read the Diary of Anne Frank in many years, but the thing I remember best about the book is her relationship with Peter. I remember the way love bloomed between them in spite of their extraordinary circumstances, and I remember thinking that it was beautiful that they loved each other and got to have that first romance experience in spite of everything. I think it’s fair, and not at all disrespectful, to draw a parallel between that love and the love that blooms between Hazel and Gus in spite of their extraordinary circumstances. I think that it’s pretty unfair to expect a history lesson with every mention of Anne Frank. Congratulations on being able to Google all those specific details you mentioned - anyone else who is unfamiliar with her story, upon seeing the movie, can go home and do the same. Maybe by leaving the parallel vague, Green is encouraging kids to find more information about Anne Frank. After all, he is a teacher, and they’re not known for just leaving the answers lying around to be found easily. You’re more likely to remember answers that you have to go looking for yourself.