I could give this book a low 1-star review if it was not hiding some really useful IFS stuff in its overly repetitive, partly uninteresting narrative.
First of all, IFS as a therapy is really useful. This book tries to make it accessible to you without having the need to pay a therapist. In that effort, it manages to do a good job, making the process more "self-help".
But the problem is that Gabby has tried to turn this rather straightforward process into a book, and she (or her publishers) have decided that that book needs to be at least 200 pages. So she ends up filling page after page with repetitive information about the process, stories that are quite generic and don't do enough to motivate you and the same check-in process at the end of each chapter. Now if you do practice that check-in process at the end of each chapter while reading this book (and assuming that you read the book over several weeks), that can be a good thing since it allows you to go through the process in different settings, possibly allowing different outcomes at the end. But that's where my other big complain about this book comes in...
For the check-in process to be really useful, you would want to do it in the form of a meditative practice and listen to it in audio form rather than read (try reading your next meditation off a page rather than listening to it and see how it goes). Gabby HAS made this process available as audio BUT it is locked behind a paid subscription to her app! That for me is completely unacceptable. We have already paid money for the book and now you want us to pay again to listen to the check-in process? To be fair, the app does have a free version to listen to but that is from the first couple of chapters. And the check-in process is supposed to change according to the contents of the later chapters, which you don't have access to without paying. Gabby you cannot have both: either the check-in process is the same in which case you have made it available to listen for free but then the rest of the 150 odd pages of your book are not justified OR your check-in process changes with the focus of each chapter, justifying the length of the book, but then making us pay to really benefit from the book is just greed!
TLDR;
Book is unnecessarily too long with repetitive information and uninspiring stories, and the check-in process audio is locked behind a pay-wall. My advice, read Chapter 3 and Chapter 11, that's all you need and that's all the book needed to be.