I'll call this 3.5 stars. why on earth goodreads can't add a half star I don't know.
I have and have read several books about buffy and I have another to read after this one. I feel like the title is a bit misleading. I would have used the word moral rather than the word spiritual, and it's not buffy herself as a guide but the morals championed in the tv series as a whole. it discusses themes of self-sacrifice, change, mortality, anger, humor, friendship, spiritual mentors, forgiveness, consequences/karma, the shadow self, and redemption.
as I'm reading books from my TBR shelf, I ask myself if I'm going to keep the book. in the first half of this I thought probably not. it just didn't seem to be saying much. the second half won me over, at least for now. there were quotes from various sources - the bible, shakespeare, spiritual writers, etc. - on the sides of some of the pages, and some of those were really good. "let us not grow weary of doing what is right" seems apropos at the moment.
in general, the book pulls out the values of self-sacrifice, friendship, redemption, and accepting the darkness inside yourself from the show. being concerned with the battle between good and evil, heroes and demons, it is obviously a show with a moral point of view, as well as some nuance, grey areas, human failure. she generally pulls good examples to make her points.
at the end there is a season guide and character guide season by season, which the author seems to provide in case someone is reading the book who is not familiar with the show. I don't know why someone would bother, but both of those were very well done. there is an interview with eliza dushku, which I guess was a coup for the author but doesn't really add much. the book in general is pretty low budget looking, there are photos of actors from the series inside, which again don't add much. I'm probably due for a rewatch of buffy but in the meantime I enjoyed revisiting episodes through this book.