Whenever I hear about a bastard child, it’s always a son. In both history and fiction, I can’t think of a single instance of a woman born out of wedlock being referred to as a bastard. Why are all the bastards men? Where are all the bastardesses?
Yes a woman could be a bastard but it’s usually masculine because it is a relic of feudal relations in which the legitimacy of daughters tended to be significantly less important to the affairs of a political unit than the legitimacy of sons because women were typically not permitted to inherit titles, property, or claims.