Specially on the traditional sense of the word. I believe based on Ilima's presentation the pink hair, the sort of amulet on their ponytail, but also their male or non gender-specific cothing, and the fact that they seem very caring, calm, and collected, (from what we've seen on the trailer), and are a trial captain, which seems to be a position of importance in Alolan tradition and a sort of teacher in its own way, align with what a Māhū is supposed to be. In traditional Hawaiian culture, Māhū's ability to embrace the traits of both genders empowers them as healers, caregivers and teachers. Māhū are people that embrace both masculine and feminine traits and live in a sort of middle ground. In Hawaiian culture a third 'gender' exist, called Māhū.
People cannot seem to be able to tell if Ilima is a woman or a man, and I believe that's exactly the point. Ilima specializes in normal typing and their appearance has been a point of discussion lately. So in the latest trailers we've been shown what one of the trail captains looks like.
