I was going to make one for male characters and add the male ones to that category. Haven't gone around to doing it yet. Since I've been adding a good number of human characters, decided to organize them further. Most of the fandom wikis I work on (e.g. Marvel, Shadowrun, DC, Villains, Heroes, etc) have categories dividing male and female characters, so I guess out of habit I created the female character category.
Don't know. I think it can be either. Originally I planned it only for human or humanoid characters. Kind of hard on the Great Old Ones. Some of them are implied to be feminine, some masculine, and it's not clear on a whole bunch of them as to what gender they are if any. I think it's best to keep the female characters category and later the male characters category to humanoids or humanoid like entities, and any alien characters. Great Old Ones and Outer Gods are by their nature, unfathomable eldritch entities. In reality, such entities don't have a gender.