I recently made a headcanon for Avanna's origins as a Zero-G Vocaloid: Zero-G sent a couple of talent scouts to Ireland with an interest in recruiting a "Celtic" singer, and though they searched among professionals, upon one of them hearing soft singing nearby as they were walking, he found the singer's voice gorgeous and decided she was the one. And thus, a freckle-faced girl (who also happened to be part-elf) was pulled off the streets of Dublin to become a professional singer. (Not that she was necessarily living on the streets, more that she just happened to be in the right place at the right time.)
She felt depressed for a while at the news that they couldn't find the right male singer to be her promised counterpart, having searched Ireland, Scotland, Wales and even the Isle of Man. Though she suggested her friend Dariusz (a concept character Avanna's artist drew), it turned out that unfortunately he couldn't sing, so he couldn't be her counterpart. Avanna and Dariusz remain friends and keep in touch.