Aftershock — Chris Archer

In the sixth book of this middle grade sci-fi series, a teen-turned-alien gains high-voltage powers to zap her enemies, if they don't get her first.
 
Up until her thirteenth birthday, Toni Douglas's only superpower was shopping. But on the very day she's celebrating becoming a teenager with a trip to the mall, she gets arrested for shoplifting! As if! Then a gang of kids come after her for no apparent reason. Good thing a bolt of lightning zaps those jerks before they could get their hands on her. It's like a birthday wish come true -- until Toni realizes the bolt didn't come from the sky, but from her.
 
Toni's electrifying new life should be exciting, only it's anything but. Having special powers comes with consequences, like the alien assassins on a mission to kill her. But growing up in Metier, the UFO capital of the north, has prepared Toni for this moment. And with a little creativity, she's ready to face down an extraterrestrial attack.