I've always assumed she was a Kilwala (and a girl but, I could be wrong). O.O But the Poyozo Dolls and Kilwala's look alike. Maybe a Poyozo is a doll OF a Kilwala?
I think the little white creature with the Nu is named Mamo in the OVA itself, right? Which means Kilwala? Also her ears are pointed like a Kilwala rather than down like the Poyozo so i'm leaning towards Kilwala.