So Tilarna Exedilica came from an alien world where fairies exists, but she looks like an human. What race is she supposed to be ?
... an inexperienced Semanian ...
Roth speaking about Tilarna
You're no longer even human!
Tilarna speaking to someone of her own race.
As far as I know what "Semani" and "Semanian" precisely means has not been revealed in the first three episodes. However it is not the country, as she is from the Farbani Kingdom and speaks in Farbani:
A VIP from the Farbani Kingdom is arriving early tomorrow morning.
Then why didn't you speak to me in Farbani