Ensign Angie Kirby was a Starfleet operations division officer who served aboard the USS Defiant, under Captain Benjamin Sisko during the 2370s.
A week after she came aboard, in late 2373, the Defiant entered the atmosphere of a planet (later named "Gaia") and discovered a settlement of the crew's descendants from an alternate timeline. In the alternate timeline, the crew of the Defiant were sent back in time 200 years, and marooned on the planet.
In this timeline, Angie Kirby and Doctor Bashir married and procreated, leaving the planet "crawling with Bashirs" by the time the Defiant made its visit. Upon learning of this fact, Bashir was confused, as he'd never met the woman prior to discovering their descendants. Bashir found her "gorgeous" and intended to ask her for a date when they returned to Deep Space 9. He felt that if they were compatible on Gaia, they might be able to make a go of it on the station.
When the Defiant failed to go back in time and fulfill its supposed "destiny", the colony (and therefore their descendants) presumably ceased to exist. (DS9: "Children of Time")
In 2374, Kirby served aboard the Defiant during the war between the Dominion and the Federation. She was present when Captain Sisko performed a ritual, he placed a discharged phaser array power cell on a rack at the mess hall of the Defiant. She participated in an attack on a Dominion sensor array in the Argolis Cluster. Afterward, she found it difficult to believe that Julian Bashir had helmed the Defiant after Lieutenant Haj had been injured. Bashir then asked Jadzia Dax to confirm his story to Kirby. Kirby was also present when Dax performed the ritual in the mess hall following the successful mission. (DS9: "Behind the Lines")
Angie Kirby was portrayed by an unknown actress in "Behind the Lines".