Some personality, backstory and skill ideas for her:
-for personality, I think that she could be a bit like Lin Beifong from Korra but a bit more "chill" and younger.
-she could be the 3rd in command in Naho and would be respected by the other arbiters and villagers. She would let Gali stay in the arbiters because she would be one of the few to have faith in her and would be like a mentor to Gali.
-fastest swimmer in Naho, often a bit too agressive, reckless tactics but always successfull, a better fighter than Tahu and Kopaka before they became the toa, artist in free time (the "flames" on her armor would represent her rage
These are just some of my ideas for G3 Dalu.
Also, it took me two days to make the rau design and I think it turned out great.