These are dystopian but she may not have read them - Bloodtide and Bloodsong by Melvin Burgess (post-apocalyptic London but the stories based on the Icelandic 'Volsunga' saga)
Also in the fantasy/dystopia vein - The Traitor Game by BR Collins (set in our world and a world made up by two teenagers in it
Sapphique and Incarceron by Catherine Fisher
I would also very much recommend Useful Idiots and The Eclipse of the Century by Jan Mark.
Also all of the Dance sequence by Aidan Chambers (winner of Hans Christian Anderson award) - Breaktime, Now I Know, The Toll Bridge, Dance on My Grave, Postcards from No-Man's Land (winner of Carnegie/Printz), and The Pillowbook of Cordelia Kenn.
Also -
Mal Peet - Life: An Exploded Diagram (set in 1960's around the Cuban Missile Crisis)
Neal Shusterman - Unwind (dystopian novel about how unwanted/ASBO teens under 17 can be 'unwound' for their body parts)
Kevin Brooks - Lucas (strange youth incomer onto Scottish island meets resistance to his presence)
All of Sonya Hartnett's books - Sleeping Dogs, What the Birds See, Surrender, The Ghost Child, Butterfly, Thursday's Child
Also, Little Brother by Cory Doctorow (teens in futuristic US who are subverting the govt's totalitarian control via the internet/technology)
Most of my kids are post-14 yrs now but they would seriously rate all of these books in various ways. They had read most of the usual available series of books too - Mortal Engines/Piratica/Garth Nix/Noughts/Crosses/Charlie Higson's zombies etc etc etc