Depends on her personality theme and powers. also, villains should wear less, usually, make them skanks. Someone who bills herself as "Hero Woman, Champion of peace and liberty!" can get away with either a combat leotard if she's mostly invulnerable or a full suit of lightweight armor with a cape and helmet if she's a regular human or close to that. Meanwhile, it would be weird and stupid if "Jungle Girl, shipwrecked as a lass and raised by psychic Orangutans on a remote jungle island" DIDN'T wear a loincloth and home-made bra-wrap. Similarly, "Lady Lochstone, Scottish Time Travelling Steampunk Gadgeteer" Should wear a big stupid looking dress and be loathe to show any more than her ankles, because that's what fits her character best. Additionally, a girl who's power is "Grows extra arms at will like a Hindu goddess" should probably wear a half-shirt at most so her extra arms don;t awkwardly bunch up inside her top.
It's all about the girl's personality, theme and powers. Do what's fun and makes sense. You want to draw a super slut? Make that part of her personality, she likes to wear provocative clothing because her body distracts bad guys or something. Or just say she loves dressing like a skank and if she didn't have powers she'd be a showgirl because she loves dancing around and dressing skanky. Want to draw a girl in a big frilly dress? Give her a reason to.