Granddaughter of George Hammond and older sister to Kayla. Following a day at school Tessa and Kayla were briefly kidnapped by a rogue arm of the N.I.D. who hoped to send a message to General Hammond about the insecurity of his family in hopes that he would resign. They were taken for a brief ride in a car and then dropped off at home.
This tactic worked, and Hammond temporarily resigned -- until Robert Kinsey was convinced (under pressure from Jack O'Neill) to drop the matter.
FIRST APPEARED - Chain Reaction
Crystal Skull - General Hammond mentions Tessa when he speaks on the phone with his granddaughter, Kayla.
Chain Reaction - Tessa and her younger sister Kayla are briefly kidnapped by the N.I.D. to convince General Hammond to resign from Stargate Command, lest something worse happen to his family.