Written by a very brave woman. Harrowing does not begin to describe this book.
One phrase used in Quran surahs (chapters) is "ma malakat aymanukum" (literally "what your right hand possesses," with a correct interpretation being "those whom you own as slaves"). The surahs mentioning this are the ones Islamic State uses to justify its use of Yazidi and Christian females as sex slaves.
The reason Islamic State considers Yazidis to be devil worshippers has to do with ignorance of the Yazidi religion. Yazidis' Peacock Angel has one or two things in common with the Islamic Shaytan the Tempter who refused God's test to bow down to Adam. Muslims first confused the two in the fifteenth century and initiated their genocide against Yazidis which has never stopped.