Penelope "Penny" Gadget is Inspector Gadget's niece, and the deuteragonist of the Inspector Gadget series.
She and Brain do most of the work because of Gadget's cluelessness and incompetence. Penny secretly helps her uncle Gadget with his missions, but it is Gadget who ends up getting all the credit in the end, which actually is beneficial because if Claw knew Penny was the real hero, she'd be in serious danger.
She is currently voiced by Tara Strong who also voiced Rocket J. Squirrel.