Penny doesn't get quite as many opportunities to be Badass in Gadget and the Gadgetinis as she does in Inspector Gadget, but she does get her moments every once in a while: particularly she can get very dangerous if you threaten the people she cares about. Two that stand out are her taking down a giant mutant carnivorous plant with a pesticide gun in "Get Gadget," and remote controlling the Gadgetinis to give a gang of marauding M.A.D Agents just what they desrve in "Nice Guys Are Finished" (while clearly enjoying herself much more than she should), both times complete with Pre-Ass-Kicking One-Liner. "Lets show these goons what happens when you mess with my Uncle Gadget!" indeed.
Gadget himself gets one in the first episode "Don't Call Me Gadget", where he dispatches Dr. Claw's M.A.D. Agents while under the effects of the aliens' intelligence reducing-increasing device.