She had completely normal parents, raised in a completely normal village but her village didn't accept her and in turn didn't accept her family. Though her parents loved her because of her they became broke. So she turned to stealing, she takes what people won't miss, sell it then repeat. After a while of keeping her home afloat she moves out to become an adventurer and steal some more. Though she was bullied as a child it didn't stop her from making friends in her adult life.
She is a kleptomaniac, she steals for the fun of it and can't stop herself. Octavia genuinely doesn't get what's wrong with stealing what people won't miss. She loves her home and has a loyalty to it but that's it. Friends are easily cast aside and she would gladly turn them in if it meant making a profit.