This is from the US flap copy of Demon's Surrender (posted by Sarah):
"The Goblin Market, where lives are won and lost and magic is bought and sold, has always been the center of Sin’s world. Now the war between magicians and the Market is escalating, and her position as future leader of the Market is threatened by a rival. Sin knows Mae can never really take control of the Market: Mae is a tourist and her brother Jamie is not only a powerful magician but the Aventurine Circle's newest and deadliest weapon. But as the Market gains strange new allies, support for Mae is growing, and Sin's only chance of leading the Market is to accomplish an impossible task.
Among the most dangerous of the Market's allies are the enigmatic Ryves brothers: Nick, who was once more than Sin's friend and whose demonic nature she cannot forget, and Alan, who has always been Sin's enemy and who she now owes a debt she cannot repay. Even as their unlikely band discovers common ground and new feelings arise between them, Sin realizes the brothers pose a greater danger than she dreamed. Alan is marked - and being tortured - by the magicians, and Nick seems to be working for them.
When Sin's family secrets are revealed, Alan's plans are rendered useless and betrayal comes from someone they trusted, a terrible sacrifice has to be made if anyone is going to survive the final battle.
The demon's surrender could destroy them all."
"Sophie Mercer thought she was a witch.
That was the whole reason she was sent to Hex Hall, a reform school for delinquent Prodigium (aka witches, shapeshifters, and fairies). But that was before she discovered the family secret, and that her hot crush, Archer Cross, is an agent for The Eye, a group bent on wiping Prodigium off the face of the earth.
Turns out, Sophie’s a demon, one of only two in the world—the other being her father. What’s worse, she has powers that threaten the lives of everyone she loves. Which is precisely why Sophie decides she must go to London for the Removal, a dangerous procedure that will destroy her powers.
But once Sophie arrives she makes a shocking discovery. Her new friends? They’re demons too. Meaning someone is raising them in secret with creepy plans to use their powers, and probably not for good. Meanwhile, The Eye is set on hunting Sophie down, and they’re using Archer to do it. But it’s not like she has feelings for him anymore. Does she?"
Lastly, we have Shimmer by Alyson Noel. This is the book two of Radiance, the spin-off from the Immortal series, which now focus on Riley - Ever's sister.