On one hand, who gave that brainless blonde a stunner? On the other hand, it must be her brainless blonde mother.
Well, Carol seems to actually be more clever than she thinks, and she never used it when it wasn't necessary.
Holy shit I fucking KNEW Carol had the highest power level in this manga
Edit: On further thought, given the fact that she's from a rich family I guess it's kind of a no-brainer that her parents would equip her with some self-defense tools.
I remember when carol's mom was like "You're like a cake with a cherry on top, so never let anyone eat your cherry". This explains why she carries a taser.