It depends on the ending you chose at the end of Fable: The Lost Chapters. If you wear Jack of Blades' mask then it will result in the Hero of Oakvale's death where Jack takes over their body and lives to continue ruling Albion in an era of darkness. If you destroy Jack's mask then the Hero of Oakvale leaves and it is implied that he dies of old age alongside his family.
There are Rumours that the Hero of Oakvale is still alive as people with archon blood can live forever. that explains why Theresa is still alive