as for her background, she was raised by a cult as an idol, the leader being her father of coarse. The goddess being that of beauty and love, and related to a lot of death and war… the rituals of the goddess having having marked Fizzy, both phonically, mentaly, and magically.
Fortunately the cult got burnt to the ground after going raider, but the ponies who did it couldn't bring themselves to harm Fizzy, and left her in Friendship City, seeing her as harmless. there she would become an apprentice to the local cola brewer, and develop a love and addiction to cola.