Rillao, a Firrerreo woman strong in the Force, received training from Darth Vader alongside her spouse, Hethrir. Her aptitude for utilizing the Force for mending and curing created a conflict with the tenets of the dark side as espoused by her instructor. She resisted succumbing to the dark side, despite the attempts of Vader and her husband.
After she witnessed Hethrir condemning their homeworld, Firrerre, to destruction and discovered Darth Vader's scheme to corrupt their unborn offspring, Rillao escaped to a secluded world. She successfully avoided capture for a number of years, raising her son, Tigris, who lacked any Force abilities. Eventually, Hethrir located Rillao, imprisoning her in a torture web aboard one of his sleeper ships and abducting Tigris. Fourteen years following the Battle of Yavin, Leia Organa Solo encountered Rillao during her search for her own missing offspring, and convinced her to assist in confronting Hethrir.
Following her reunion with Tigris, who had been brainwashed by Hethrir to believe his mother was a betrayer that stole his Force potential, and the defeat of Hethrir, the mother and son resolved to rebuild their relationship, despite the initial hostility from the boy.