[The girl looks like she could have Earth Kingdom ancestry, but... the hair. Hair colors that aren't black or brown, or gray, are extraordinarily rare on Kuvira's Earth. Maybe it's Varribleach.

She can sense any metal on Fuu. There is so little stone and earth and metal here, things stand out more to her bending.]

Fae? If these are spirits, they probably wouldn't have a great deal of structure, but something is responsible for this.

This doesn't seem as strange as what I would have expected from the Spirit World. [yes, being tiny and winged and in a giant tree isn't as weird as the Spirit World.]