Being female has nothing to do with clothes. Male don't come with clothes. That's the definition of male. Someone without developed breasts is probably male. Someone without developed breasts making the choices of a woman is a woman.
Sex is anatomical difference based on reproductive organs.
Gender is the social notions we build around those differences . Sex has remained unchanged though humans, and in fact across mammals. Gender changes like the wind, with lots of different models. Sex is natural, essential, enduring. Gender is social, constructed, ephemeral.