This is an adorable little love story, but it's such a heartfelt one that I enjoyed every minute of it.
The authors do their best to prop up their narrative of RBG's life with facts - in fact, there is an extensive notes and references section, just like you'd see in a heavily researched non-fiction book. They also provide annotations for the full text of RBG's dissents, which is both welcome and done particularly well. They make their main points several times without resorting to true repetition - such as, RBG's reluctance to move full steam ahead on particular feminist agendas, certain that the test of time was the better approach.
I read the book both before and after watching the documentary (with the same "authors") and they're the same story. The documentary just has representative visuals. Each are adorable, heartfelt, and most importantly useful in today's climate.