Liar - Francine Pascal

Seventeen-year-old Gaia Moore is not your typical high school senior. Her mother is dead and her father, a secret agent, abandonned her years ago. But before he did, he taught her self-preservation because he knew she would need it. She's a black belt in karate, she's multilingual and has an extraordinary abilty - fearlessness. Gaia is genetically enhanced to not feel fear. Since her father left she's been shunted around from one foster family to another, that is until she is placed with George Niven, Gaia's only link to her father. Now things get dangerous. There are a lot of people after Gaia but Gaia doesn't care. Her world is about to explode with terrorists, computer hackers, government spies and people bent on taking her apart because she has no fear.