Cassandra Fortlage is a thief running amongst the darkness of Golarion. She gets by solely on the scraps she manages to scrounge from the more fortunate members of society, be it gold, jewels, art, or family heirlooms. However, her most prized quarry are items of arcane origin. Ever since she was a little girl she has had a fascination with magic, however she never had the support or resources to study it, so she sustained her curiosity by simply taking from wizards, witches, and sorceres whatever magic items weren't nailed down.
As a result of the dangerousness of her targets, she is always on the run from fear of these arcane spellcasters she has robbed.
Cassandra was born in a proud northern nation to two Halfling soldiers, whose identities are unknown to her, as when Cassandra was very young her parents were sent off to fight in some unnecessary war and both of them lost their lives in the hellish battles. So Cassandra was left on her own with no one to take care of her. As a result, he spent her whole life as a street urchin living off the scraps of society through charity or less honorable means.
Eventually, her time in the North came to a close as the people of her village grew tired of her constant shenanigans and thievery, so she fled south to Solsun. It was here that she fell into a thieve's guild. She lived and moved with them, learning more skills to aid in her acquisition of magical devices. Soon enough her thievery got the entirety of her foster family in trouble with some local spellcasters and they were forced to flee. This led her to Selsey to seek out an old family friend. And since then she's quietly inhabited Selsey.
What caused so much fuss that caused her whole family to flee? She managed to filch what she believes to be a Wand of Detect Magic and two Potions of Mage Armor from a pitiful Wizard that could barely cast Cantrips. She believes she's better off with it. (I took the Rich Parents trait to be able to afford the Wand, and purely changed the flavor text of the trait.)