It's very good, really impressive demo. My feedback would be, Maya needs to keep quiet a little longer after asking a question. She would ask something, then as I thought about my reply, already be on to the next thing. It left me with the impression she was a babbler (which is not an unrealistic model of how humans are, but it would be cool to be able to dial such traits up or down to taste).
I suppose the lack of visual cues probably hinders things in that regard.