Petra Chan was a Bajoran girl. Petra was a childhood friend of Kira Nerys, who considered Petra to be a sisterly figure.
In 2353, Petra was one of several young girls from Kira's village who were taken away by the Cardassians. Kira tried to convince the Cardassians to take her in Petra's place. Istani Reyla told Kira that the Prophets would look after Petra Chan. (ST - Terok Nor novel: Night of the Wolves)