I've just read the book. The vast majority of it focuses intimately on the filth, squalor & bodily functions of every description in Eileen's life. Interactions between Eileen & Rebecca are few & far between, mainly lived out in Eileen's fantasies, even then squalid & sparse. Similarly with her father, who is mostly drunk & verbally abusive & never engages in any meaningful way whatsoever. It's worth reading but I was glad to finish it. Seems to be about broken relationships, disfunctional families, everyday squalor & desperate escape tactics. Not sure I'd want to watch a film that's true to the book !!!