Where in Fable 2 do you find your wife on the mission rescue?

You don't find your wife on the mission "Rescue" in Fable 2. That mission is focused on rescuing your kidnapped sibling from the villainous Jack of Blades.

Your wife, Theresa, is not involved in that mission. She is a recurring character in the game but doesn't play a significant role in the "Rescue" mission.