She related to Kira the story of James T. Kirk's visit to their reality a century earlier and how Spock had followed Kirk's advice and began to preach reforms of the Terran Empire, leading to its takeover by the Alliance.
Kira later encountered Commander Benjamin Sisko when he was brought to Terok Nor by Miles O'Brien. Believing him to be "her" Sisko, the Intendant was duped by him, long enough for him to convince Jennifer Sisko to join the Terran Rebellion. (DS9 episode: "Through the Looking Glass")
After the Rebellion took Terok Nor, the Intendant was captured by them before she was able to escape. Captain Ben Sisko visited her in the brig, and attempted to convince her to tell him a way of delaying Regent Worf's ships. She did so, telling him their sensors could be fooled by warp "shadows."
Kira was later captured again - this time by the Alliance - and incarcerated on the Regent's flagship. She was later able to escape once more, after the cloaking device was sabotaged by Rom. (DS9 episode: "The Emperor's New Cloak")
Kira later planned to take over the Alliance - and more. She was able to convince Regent Martok to let her use the Klingon Ninth Fleet.
In the mirror universe, Kira Nerys was the Klingon-Cardassian Alliance Intendant of the Bajor system. Kira commanded the space station Terok Nor in orbit of Bajor from at least 2370 until 2372, when the station was captured by the Terran rebellion. (DS9: "Crossover", "Shattered Mirror")