@Lionhearted
Kyoshi warriors are allowed! And to be honest, given the traditional dress, if you wanted to just use Suki art, that would be okay. One I had on my Pinterest, if it's needed. Some quick ideas, mixing and matching is okay if you want (or you can ignore them):

- Kyoshi Island as a whole is canon levels of 'neutral' - especially since the war is relatively young. It's no Hundred Year War yet - but your character is not and wishes to head to the conflict and assist the Earth Kingdom military.

- Kyoshi Island wants to know what is going on, so send her as a scout and/or diplomat to Ba Sing Se.

- Potentially they could want to advertise their unique style and way of life, so looking for recruits in the city or training newbies (probably in the Upper or Middle Rings, although it could be a personal quest, in which case the Lower Ring could also work).

- Alternatively, since I think the chances of having two Kyoshi Warriors is low, you could also go non-canon and have them be in the war due to an attack on their island, which may or may not have been repelled. If you do choose to add to the lore of this alternate timeline, let me know and I'll add whatever you want to the... Earth Kingdom section? Water Tribe section? Somewhere?