Everything is lies
Helen Callaghan worked in the bookselling business before she started writing. This is her second novel. And like so many novels I have read recently, it is set in two time periods, the present of the first person narrator Sophie and the past, when her mother was young.
This second narrative level is presented by a novel, her mother secretly wrote, so we have the narrative topic of a novel in a novel.
This way Callaghan can indulge in reminiscences of her own hippy past. And Sophie finds out that nothing is what it looks to be. Thrown in are break-ins and murder, so all in all a mixture, that is a good recipe for success, as the literary agent Callaghan knows full well.