Sileen was a member of the Mistryl Shadow Guard. In 0 BBY, she formed part of the team of six warrior-women led by Manda D'ulin, where she acted as the pilot of the Skyclaw, one of the team's two starfighters.
Sileen was not immediately involved in the stormtrooper ambush at the gates of the Hammertong facility which saw the Team Prime and Pav D'armon both gunned down, but when Shada D'ukal decided to respond with a counterattack, she provided effective fire support, enabling Shada and Karoly D'ulin to steal a Strike cruiser carrying an Imperial superlaser prototype.
Subsequently, Sileen took the Skyclaw to Emberlene to fetch a freighter, leaving Cai and the Mirage to escort the cruiser to Tatooine.