Yugiri CLEARLY uses the same skeleton as Miqo'te girls. A quick examination of her animations show that hers are identical to Miqos. Look REALLY close and see that Y'shtola is either always put out of frame or in a unique pose when near Yugiri.

As for her race, I'm guessing they took the Vian'gaa concept and made modifications to make them a more attractive option. Hopefully with their own emotes when the time comes for her proper reveal.