This book is good for exploring gender identity if you're unsure or questioning, but also if you know for certain and aren't sure where to start. It's a pretty active and reflective read that helps facilitate doing some hard, honest, self-analysis as you go along. Natalia is also an amazing author and an expert on the subject, providing some much-needed, gentle-but-tough love throughout.
She is also intelligent enough to realize that one of the common problems faced by trans and non-binary individuals is being disconnected from a true sense of self and our own emotions, as dissociation and repression are common defense mechanisms against dysphoria. I get the impression that she understands that asking someone who's disconnected from their feelings to reflect on their experience isn't the easiest task, but is also aware enough to realize you're a grown adult who's made it this far and trusts that you have the self-awareness to reflect and self-analyze. Another strength of the book is while it can give you the push you need, it isn't trying to push anyone into transitioning. One of the opening chapters even discusses how transition isn't for everyone and isn't necessarily a requirement for every trans and non-binary individual.
Overall a great, quick read from an equally empathetic and intelligent expert on the subject. If you are trans, non-binary, or questioning, I highly recommend her YouTube channel and other socials as they are beyond helpful in navigating the complex and often nebulous world of gender identity.