The book opens with a hesitant and somewhat cantankerous General Leia giving a personal account of her past, in hopes of somehow inspiring others. The first-person telling of the intro holds her voice authentically, with that edge of weariness fans would fully expect. It then switches to a more distant 3rd-person perspective for the rest of the book.
"To be honest, I think this whole biography thing is a bit silly. But this archival droid won't stop following me around..."
For an early-reader chapter book, it has just the right mix of material they already know from the movies and extra motivating backstory that presents a bit of new and character-enriching information. The black and white artwork is interspersed every other page, and does a lovely job of capturing both likeness and expressions where appropriate. My kids (ages 6 and 8) read this with me in 2 sittings, and it generally held their attention and interest.
As an adult fan who grew up with the original three movies as a staple, it was satisfying to see more emotion and humanity lent to the space princess who defied the spoiled, frilly princess stereotypes with a blaster-wielding vengeance. This book gives acknowledgement to the repressed pain of her planet's destruction, weight to her personal stake and responsibilities, and even some plausibility to her biological mother's love story with Anikan that the movie didn't quite achieve. It also may pique reader's curiosity toward the late Queen of Alderaan--Leia's adopted mother, Breha.
While Royal Rebel is mindful to The Force Awakens material, it mysteriously leaves blank the entire time between the birth of Han and Leia's son, Ben, and the events of TFA. I personally found that the most disappointing aspect. It's hard to tell if the material simply hasn't been written to fit the new cannon, or if it's being withheld as a means of incurring interest in planned filler that will be released in the eventual future. (I would guess the later... because $.)
A worthwhile read for Star Wars fans, young and... er ...aging. *cough*
And unbeknownst to the creators, a heart-wrenching and timely release.