Nancy Hedford was a female human who served as a Federation Assistant Commissioner in the mid 23rd century. In 2267, she was assigned to a mission to Epsilon Canaris III in order to prevent the outbreak of war. Her mission was cut short when she contracted Sakuro's Disease, and the USS Enterprise was sent to transport her to a medical facility. The shuttlecraft sent to bring Hedford to the ship, however, was seized by an energy-based alien entity and diverted to an uncharted planetoid in the Gamma Canaris region. There, Hedford and the Enterprise officer encountered Zefram Cochrane, who had gone missing from Alpha Centauri 150 years earlier.
Hedford's medical condition worsened while grounded on the planetoid. Just before succumbing, Hedford agreed to merge with the alien, known as The Companion, who loved Cochrane but was unable to be loved by him in its alien form. Hedford and Cochrane then lived out the remainder of their normal lifespans on the planetoid. (TOS episode: "Metamorphosis")
In one alternate timeline, Hedford was a junior administrator assigned to Epsilon Canaris III in 2259, where her creative negotiations were able to keep the planet's society from collapsing. Over the following years she became a successful diplomat, and in 2264, as an ambassador, she headed the mission to have United Earth join the Coalition of Planets. (Star Trek: Myriad Universes novel: A Less Perfect Union)