Currently, we only know that she's an Electro/Sword unit according to the leak. There hasn't been any other info about her.
Kate is a Electro Sword Character.
Sayu, the little one. Is a Anemo Claymore character. https://t.co/7t5ja3uWCk
Puzzles, Secrets, and Hidden Chests in Dragonspine
ATK% VS Physical/Elemental DMG% in Genshin
Puzzles, Secrets, and Hidden Chests in Liyue