Still holding to my theory about the ending of The Woman Upstairs

I'm staying w/ my me theory, advanced in yesterday's post, that the narrator, Nora, in Claire Messud's The Woman Upstairs, is seriously delusional and her entire relationship with her student Reza and his parents is a product of her fantasy, her needs, her psychosis. As we advance toward the half-way point in this novel, Nora now begins to babysit for the 8-year-old boy - an obvious violation of boundaries if not of ethics - and she does so because, apparently, he begs his mother, he's nervous when she and her husband go out but things would be better if he could be with "Miss E." Of course there's no pay involved - because, as mother Sirena puts it, they're all like family. And Nora just eats this up, she's in ecstasy, so pleased to be beloved by this exotic couple - the man flirting with her, Sirena praising her artwork, and so on. Either the family is exploiting her weakness, which I doubt, or she's a seriously delusional woman. Interestingly, she begins helping Sirena on her art project, a creation of a "wonderland" based on the novel - that's kind of like a fun house, even dangerous. This will possibly lead to an accident of some sort - maybe involving the boy Reza. And it may be that there's no Sirena at all or that she's not an artist - all these concept-art projects are surprisingly similar, so it would make sense that Nora is actually the artist behind each (unless the similarity is the fault of Messud's imagination - she's obviously "behind" all of the characters and their art projects). This novel has a lot working against it - the whining and complaining of the narrator, the lack of significant action, the lack of specificity regarding so many aspects of the narrator's life and world - but I am kind of curious about the outcome, which portends no good.