Avian is from an elevated mountain town situated near Crownpeaks, Arcadia. She is a bird-type beastkin commonly known as a harpy, and her family is one of nobility, and quite well off. Rich/noble families are ones with colour based last named, with her being Teale. Her best friend had the last name of Scarlet, which are considered rival families, but Avian isn't one to think about family politics or other such nonsense, so she continued playing with her friend. She'd sneak out of home by any means necessary to hang out with the others.
Regardless of disputes, Avian is the oldest child and heir to her household, so she's sent out to explore and gain worldly experience before being eligible to take over- thus her reason for adventure, to explore the new world, make some friends.