I . . . what on earth. From the first pages appropriating a piece of Iranian mythology, Ms. Nahmad picks and chooses and blends pieces of different religions in a fashion like a child with a chemistry set - always most heavily returning to Christianity and the angels, which she tells us the fairies are the Earthly hand-servants of.
There are no references for the many places where she quotes "it is known" or "mortals have always known" or "it is said", or indeed for the supposedly ancient spells she teaches (despite the title, there is only one chapter, also entitled 'Fairy Spells', that covers them, and they are all in that chapter for awakening "fairy vision").
Her quoting of 'fairy-related deities' was a particularly bogglesome moment - for example quoted as three aspects of the Nature Goddess, by their Greek names, are "Diana, Artemis, and Aradia". Diana being the Roman name of the Greek goddess Artemis, and Aradia supposedly from witchcraft in Italian history from the 1300s, but never found referenced save in a single text translated (and patched with things he made up) by a single man in 1899.
As a pagan and witch walking my path for decades, I found nothing useful in this book, much that made me boggle, and a good deal that was offensive or hurtful to varying religions or beliefs.