Colorblind

Harper has a secret...and it's not that she likes girls. She has a rare and special gift: she can see how old other people will be when they pass away. Nothing she does changes this number, and that becomes especially clear when her mother dies in a car crash. With only one other person in the world who knows about and shares her gift, Harper is determined to keep her distance from everyone. Then she falls for Chloe... whose number is 16.
That means that Chloe doesn't have twelve months to live. She doesn't even have six.
She is going to be dead by the end of the summer, unless Harper can find a way to stop it.