Bella is a resident of Stoney Sept and serves as a prostitute in The Peach. She claims that she is the bastard daughter of Robert Baratheon, as her mother was a favourite of Roberts whilst he hid in the town before the Battle of the Bells.
If she is right then she is the half sister of Gendry, Mya Stone, Barra and several others, whilst also being the legal sister of King Joffrey I Baratheon, King Tommen I Baratheon and Princess Myrcella Baratheon.
A Storm of SwordsEdit
She encounters Gendry and Arya Stark when the two visit the town with the Brotherhood without Banners. Hse tries to seduce Gendry, neither knowing that they could be in fact related. Gendry declines her, but mentions her later when he gets mad at Arya.