Starfleet Academy cadet born in Tycho City on the Earth satellite Luna (known to natives as The Moon). Collins was a member of the elite Red Squad who embarked upon a three-month training cruise aboard the U.S.S. Valiant in 2374. The Valiant was caught behind enemy lines when the Dominion War broke out, and all the regular officers were killed, leaving the young cadets in charge of the ship. Collins was made acting chief petty officer under the command of acting captain Tim Watters. She greeted Jake Sisko and Ensign Nog when they were rescued by the Valiant, and she later treated Jake's wounds and befriended him. Her conversations with Jake caused her to become homesick, which led Watters to order Jake to stay away from Collins (an order which he later violated and was imprisoned for). When the over-confident Watters ordered his crew to attack a massive Dominion battleship, the Valiant was destroyed. Collins was the only member of Red Squad to survive that incident, having joined Nog and Jake in an escape pod and being rescued by the Defiant.
As a child Dorian loved to take hikes with her father upon the low-gravity surface of the Moon; she considered the barren, harsh environment to be beautiful. Every lunar morning (which occurred only once a month in Earth time) they would put on suits, hike across the Sea of Clouds and stop at the western rim to wait for the sun to come up. The lunar dawn was a shocking but highly spiritual experience for Dorian.