Sirta came from a large Andorian family with a military history. Her father served as an engineer in the Andorian Defence Force and two of her siblings joined Starfleet. When Sirta reached the proper age, she trained as a battle medic at the Andorian Academy. After graduating, she followed her father into the Defence Force, serving aboard a small starship patrolling local space. Her ship’s first assignment was to track down a group of Anti-Federation Andorian renegades. During a battle with the renegades, her ship was heavily damaged and Sirta was forced to take control of sickbay, where she treated dozens of wounded, after her Chief Medical Officer was killed in the battle.
Starfleet heard of her valour and invited her to attend Starfleet Academy, where she quickly mastered xenobiology.
On one of her first missions aboard the Incursion, following a Romulan attack on the Klingon research base Lak'Tral. Lieutenant D'Qua was part of an away team to rescue Klingon scientists and aid Klingon warriors in the battle against Romulan personnel still in the base. (TNG video game: Away Team)