Jaina Halcyon was related to the Halcyon family, which consisted of both Nejaa Halcyon and Corran Horn, among other Jedi. Like those in her bloodline before her, Jaina was unable to normally use the Force to perform such feats as telekinesis, but was able to absorb mass amounts of energy to counter her weaknesses. Jaina was believed to be raised as a Jedi within the New Jedi Order, eventually reaching the rank of Jedi Knight. She had also lived her life as a bounty hunter, and had been a member of various factions throughout her life.
Bounty hunter and back
At some point in her life, Jaina decided to abandon the ways of the Jedi for a time, becoming a bounty hunter for hire. As this happened, she took up the name Jaina Fett, supposedly to disguise her true identity to those around her. She chose the surname Fett, because of her Mandalorian heritage, and because she was a descendant of Boba Fett's granddaughter, Mirta Gev.
Jaina was eventually approached by Yamato Kamiya, the then leader of The Silent Fighters, who offered her the chance to join. She willingly signed up with them. A few months later, Jaina started up a branch of Coruscanti Industries on Coruscant, that sold new and refurbished old starships, such as ARC-170s and Firespray-Class Patrol ships.
After the appearance of the Force creature Raze, and Yamato's decision to go back to being a Jedi himself, Jaina decided to return back to the ways of the Force along with him.
Not long after Raze's final defeat, Jaina and Yamato set out to Tatooine together, to investigate rumors of a rebel alliance that operated in one of the major cities on the planet. Their suspicions proved correct when they came upon the Rebel's base in Mos Eisley. Meeting the general there, they discovered that Mos Eisley was under Imperial control and that the rebellion was created to overthrow them.
Both Jaina and Yamato agreed to help the Rebellion, but their support to the resistance didn't last long. The Imperial garrison stationed in the city happened to locate the base, surrounding it so those inside could not escape. The Rebel general was forced to surrender to the Imperial forces, while Jaina and Yamato escaped unnoticed and met up with two other members of the resistance. Together, they formed a plan to rescue the general, but Yamato was left unaware of these plans as they snuck aboard the orbiting Imperial Star Destroyer.
The rescue attempt turned out to be a near total failure, with both Jaina and Yamato being captured. It didn't take long, however, for Jaina to break out of her captivity and steal a ship. Realizing it wouldn't be easy to escape the perimeter of the star destroyer because of its tractor beam, Jaina flew her ship outside and disabled the tractor beam with her cannons. She returned to the hangar of the star destroyer where Yamato was waiting for her, and they returned to Tatooine's surface together.
Once on the surface, Yamato was upset at not only the inability that he was not informed of the Rebels' plan to rescue the general, but also the fact that it seemed to be a suicide mission and that Jaina appeared to almost abandon him on board the Imperial's starship. Acting unusually aggressive and rash, Yamato Force choked Jaina, tossing her into the hull of the starfighter they landed in, and ran off. Jaina, using her senses, was able to determine that he was heading to the planet Dromund Kaas.
After Jaina got there, she followed Yamato's trail to one of the many temples that dotted the planet. She ran into him frantically talking to another woman inside the temple, who introduced herself as Charly. Yamato, who was extremely angered by Jaina's appearance, attacked them both, easily defeating them. A Dark Jedi happened to be nearby the scene, and also met a similar fate to Jaina and Charly's when she challenged him. Help arrived not long afterward in the form of a couple of Jedi who healed both Jaina and Charly. Although Yamato was still furious, Charly was able to calm him down, and he apologized to his friends, who respectfully accepted.
Danger on Coruscant
About a half a year later, the Empire, combined with the forces of the Sith, invaded and took over Coruscant. Jaina received word that the Imperials were cleaning out the planet of any stragglers, especially Force users. Aware of this, she soon came face-to-face with a stormtrooper who asked for her identification. Using a Jedi mind trick, as any other Jedi normally would have done in such a situation, she refused. Unfortunately, the mind trick didn't quite work on the stormtrooper, confusing him, and he shot at her. Jaina ran for her life, to where the Silent Fighters's base was.
She found Yamato within the building and told him of the situation outside. Yamato, normally optimistic as he was, decided to take matters into his own hands and attempted to speak with the Imperials outside the base. After an argument that seemingly went nowhere, both Jaina and Yamato chose to fight their way out. Yamato was subdued by Imperial forces, but Jaina escaped and fled to Kashyyyk, where other Jedi had been taking up refuge. She put a small, disguised group of Jedi together to rescue Yamato from Coruscant, that eventually was successful. Knowing that if they went back to Coruscant they would be killed, Jaina and Yamato abandoned their base and headed to the Smuggler's Moon of Nar Shaddaa, where they hoped to keep a low profile away from the Empire and the Sith. Jaina went back to bounty hunting, resuming her "Jaina Fett" alias.
Jaina was approached by Yamato, who became a member of Black Sun, as part of his low profile, asked her about joining them. She agreed, and together they met with Cayce Urriah, who came to agreement with both Jaina and Yamato about acquiring the services of both Coruscanti Industries and The Silent Fighters. Sometime later on, Jaina joined Ordo Jin, a very small band of neutral and Grey Jedi that resided at Nar Shaddaa.
Behind the scenes
Jaina Halcyon is a character within the Star Wars Roleplaying Community in the virtual online game, Second Life.