As a child, Kestra tried to teach Deanna methods of creating mental shields that would keep their mother out of her mind.
She eventually became involved in the Terran Rebellion. In that year, Kestra returned to Betazed with Jean-Luc Picard in order to assassinate Lursa and B'Etor. While Picard was on the planet, Kestra remained on the Stargazer. When the Duras sisters arrived, their ship detected the Stargazer and destroyed it, killing Kestra. (TNG - Mirror Universe short story: "The Sacred Chalice")