Petra was a female Bajoran and daughter of Rizo born in 2351. In 2370, she took part in the hijacking of the antimatter tanker Phoenix. She later stowed away on the tanker to help her father. When she was discovered, she was allowed to stay with her father in a cargo bay. Jadzia Dax promised to help her out when they got back to the Federation.
During the Occupation of Bajor, when Petra was four, her mother was taken by Cardassians. It was unknown what truly happened of her, but Rizo figured she was raped to death. Rizo then took Petra and joined the Bajoran Resistance. (DS9 novel: Antimatter)