A Force-sensitive Miraluka female, Marr joined the Jedi Order and served as a Jedi Knight around the year 3641 BBY. During the later stages of the Cold War between the Galactic Republic and Sith Empire, Marr was commanded by Jedi Master Jun Seros to lead a cadre of Republic Strategic Information Service shadow operatives to search for the latest Grand Champion of the Great Hunt, responsible for the death of Jedi Master Kellian Jarro, a close friend to Master Seros. Their search brought them to Nar Shaddaa, where they stormed a party being hosted by Bloodworthy, Jewl'a Nightbringer and the Defenestrator for the new Grand Champion. The bounty hunters refused to give up their comrade's whereabouts and were all killed in the ensuing fight. Adeline reported to Seros via holo about the apparent dead end when the Grand Champion arrived. Seros offered the bounty hunter one last chance to surrender, but the Champion refused, angered at their comrades' deaths. Before anyone could react, the Defenestrator's body activated a self-destruct, causing a brief confusion to allow the Grand Champion to kill Adeline and her allies.
A female Miraluka with black hair and light skin, Marr was blind as is typical to all members of her species. She wielded a blue lightsaber in combat.
Adeline Marr was created for Star Wars: The Old Republic, a massively multiplayer online role-playing game released by BioWare on December 20, 2011. She appears in the Bounty Hunter class mission "Notorious," where the player is granted conversation options to try and settle with Marr and Jun Seros peacefully or with violence, but whichever option the player chooses, Seros always commands Adeline to attack the Bounty Hunter.