Faile's parents are Hetalia and Weedl (wife and husband).  They were the ones who found her alive around the flaming rubble of her home.

Her sprite companion Aardist is a child hood friend from Lofton.

As Faile grew up, she became of the.fact that she was out of place with the fairies, who were often 1/3 her size.  She came more curious about the human town.  She felt isolated in community, although she had her parents, Aardist, and a couple of friends.  She became fixated on finding that community in other human towns. 
Part of this intertwined with her anger at losing her human heritage and her human parents.   She made a deal with Aurora for magic power in this quest to find the people who destroyed her home.   
Aurora (don't know her personality but assuming she is good) has had a few interactions with Faile since there are rarely any humans in Lofton (I assume).   They are not friends, more Iike nobel and servant,  how I imagine.   Since Faile is LN and Aurora is good, there can be some future conflicts if Faile goes overboard.  Aurora is aware of Faile's anger and is emphatic for justice, maybe not so for the means.