Well, they have aether, because they're alive; "aether" is just the name the residents of Hydaelyn give to The Imperceptible Life Force Of The Universe and also The Stuff Of Souls, so any Garlean at least has it.

They can't do much with it, though; the lore panel was clear on this. They can't manipulate aether, so presumably they can't "naturally" use aetherytes and whatnot. They'd need a technological solution for the same thing.