Duvall was trained to be a Starfleet pilot, valedictorian of her Academy class. Her first assigment was on the Harmony 2 as helmsman. After that, she became the first officer of the prototype starship Constellation.
Her first command was the Maximillian, then Daedalus a prototype vessel as well equiped with a cascading ion drive (Cid). The Daedalus attempted it's first voyage with the Cid, but a catastrophic ion-cascade reaction utterly destroyed the ship, and killed it's entire crew including Captain Duvall. (ENT novels: Daedalus, Daedalus's Children)
In an alternate timelines the Daedalus survived the catastrophe and ended up in the Denari system. The Denari captured Daedalus and her crew. Captain Duvall, who was carrying Jonathan Archer's child, surrendered herself and Daedalus's database to Denari's dictator General Sadir Lyatt. In the next fourteen years she was Sadir's wife and the mother of "his child". She died in an explosion on the prime universe Enterprise (NX-01). (ENT novels: Daedalus, Daedalus's Children)