Mandanna does a good job portraying her characters' feelings and relationships, especially Eva's fear and resentment at her untenable situation. The unsympathetic characters also have dimensions beyond merely being mean to the protagonist. She even has a romance that develops gradually out of two individuals (gasp!) knowing one another over time! And her writing is fine. I wish she had written a different book.
If, like me, you pick this up out of topical interest, you are going to be disappointed. The world-building, pretty much all of it, from the legal issues to the motivations of people who would pay for the (presumably hugely expensive) copies of their children to how those copies are raised, trained, and utilized -- Makes. No. Sense.
I was fine when we stayed in Eva's head, hearing her struggle to be herself as well as Amarra, but any time she or one of the other characters started explaining anything about the echoes I went "Gah! That makes no sense! Why would anyone think/do/want that?!" I mean this is terms of both practical issues like, "Why would you raise someone in near-isolation in a tiny town in England if they were meant to replicate a popular schoolgirl from Bangalore?" and psychological questions like "What the hell kind of parent would want to pretend a copy was their dead child?!"
The things that were interesting about the people-copying premise have been treated better in several earlier books. If you don't require teen romance, I recommend Lois Bujold's two-part [b:Brothers in Arms|296182|Brothers in Arms (Vorkosigan Saga, #7)|Lois McMaster Bujold|http://d.gr-assets.com/books/1353351698s/296182.jpg|1808918] and [b:Mirror Dance|61909|Mirror Dance (Vorkosigan Saga, #9)|Lois McMaster Bujold|http://d.gr-assets.com/books/1297831387s/61909.jpg|287351].