You Can Be a Cyborg When You're Older — Richard Roberts

In the bleak future of West Angel City, Vanity Rose is having a great time. She has a loving robot caretaker, a fake elf for a sister, and she roams the walls of West Angel's endless skyscrapers every night, thanks to her precious gravity shoes.

What Vanity doesn't have are money and adventure, but she has a plan to get both. She's going to walk the dark side, joining the thieves and mercenaries who get paid to do all the little jobs that make a corrupt city go around. She'll only have to deal with killer robots, vengeance-crazed and not very bright computer programs, cyborg vampires, telepathic capybaras, mean girl mech pilots, and have every homemade weapon in the city pointed at her.

Fourteen is old enough for that, right?