Saavik in the mirror universe was a member of Imperial Starfleet and became new-Emperor Spock's proteg'e and student after he sponsored her application to Starfleet. With his help, her career advanced to the point she became Captain of the ISS Enterprise. She also did all she could to help Spock's master plan of destroying the Klingon and Cardassian species by using the entire Vulcan population as sleeper agents, who when activated, would lead a massive uprising against their impending Alliance.
When the Alliance formed and began conquering the Terran Empire, Spock asked her to retire from Starfleet and return to Vulcan in preperation for the invasion. Saavik reluctantly agreed. Saavik's last known appearence was when she successfully became a domestic serveant in the Cardassian Union and remained undercover for the Vulcan Resistance for many years. (TOS novel: Glass Empires)