To be fair heels are also kind of an arbitrary concept in the world of super hero comics thanks to the revolving door of artists depicting the same female characters in the same timeframe with the supposedly same costumes differently in some details including footwear. Which seems to be always up to the preference or focus of the artist (or how much they can bother about such details).
For example just compare how various artist depict some of Storm's classic costumes most notably the white 90's one.
So the heels on same costume can go from short to high to flat sometimes within the same story or even the same comic. All depending on the artist.