Jenny is a 'century baby,' the Spirit of the 20th Century, to be exact. This means that as of right now she has a hundred years of living behind her, but more importantly, she is very durable physically (she can be wounded, but she heals fast, and she is incredibly, staggeringly hard to actually kill) and can not only control electricity to a ridiculous degree, she is made of electricity in some weird mystic way that is totally compatible with being made of flesh and blood at the same time.

More about electricity: Jenny can generate electricity ranging from tiny sparks to lightning bolts and sometimes huge electrical storms (though they can be taxing), she can detect electrical fields including the ones that denote human presence, she can subtract/cancel electrical fields including the one powering the human brain, she can turn herself into pure energy and travel through a power grid or just be a giant transparent sparky pissed off Jenny (I do not even know), and she can mask her presence from sensor technology.