At some point prior to 9 ABY, Callahan enlisted in the New Republic Starfighter Corps as a pilot, and eventually obtained the rank of lieutenant.
Sometime around that same year, Callahan, along with Captain Porter, were stationed on the planet of Lothal and provided security for a festival celebrating the planet's independence from the Galactic Empire in the capital city. After Sabine Wren had failed to attend the festivities, Governor Ryder Azadi ordered Callahan and Porter to locate her and bring her into the city. Piloting two E-wing escort fighters, Callahan and Porter spotted Wren riding out of the city on a speeder bike and moved to intercept her. As Captain Porter attempted to persuade Wren to turn around, Callahan landed her E-wing further down Lothal's highway to act as a roadblock. Callahan became increasingly panicked as Wren continued barreling toward her, before eventually abandoning the cockpit of her E-wing in fear as the Mandalorian managed to slip past Callahan's E-wing by ducking underneath it as she continued speeding out towards the city's comm tower.
Callahan was a human female. While initially confident that Sabine Wren would be intimidated by the sight of two New Republic E-wings and return to Lothal's capital, Callahan would soon after abandon her starfighter in fear for her life after it appeared that Wren would crash in to it.
Callahan was first appeared in the first episode of the Disney+ series Ahsoka, which released on August 22, 2023. Callahan was portrayed by Michele Weaver.