Aww I am surprised no one has said Brothers as female Ok on a more serious note Cactaur is male. His moustache gives it away.
BTW you forgot about Odin and Gilgamesh. Even though you can't equip them they should have genders too.

Squall always has Diablo, Shiva, and Eden
Zell: Ifrit, Doomtrain, Siren
All others are mixed matched.