Water, Earth, Fire, and Air [class]

[Yuki Akuma]

We don't know if those girls in the healing lesson were the entirety of female novice benders in the city, or just the ones able to heal.

There could have been ten times that number who just couldn't heal, so weren't allowed lessons at all.

But, really, why does it matter? Those without the 'gift' don't take healing forms, or when they do take them, they discover their gift! It's like psionic classes, or the sorcerer. Some people have the gift, most don't. People who start as something else and gain a level in sorcerer later on had the gift all along, but only recently discovered it. People who never become sorcerers never had the gift, or it was never brought to the surface.