Callahan was a human female serving the New Republic. Holding the military rank of lieutenant, she functioned as a pilot. She, along with Captain Porter, was stationed on the planet of Lothal, where they were instructed by Governor Ryder Azadi to find Commander Sabine Wren.
Before 9 ABY, Callahan enlisted as a pilot in the New Republic Starfighter Corps, eventually rising to the rank of lieutenant.
Around that year, Callahan and Captain Porter were assigned to Lothal, providing security for a festival celebrating the planet's independence from the Galactic Empire in the capital city. When Sabine Wren didn't show up to the festivities, Ryder Azadi, the Governor, ordered Callahan and Porter to locate her and bring her to the city. Flying two E-wing starfighters, Callahan and Porter noticed Wren riding a speeder bike away from the city and moved to stop her. While Captain Porter attempted to convince Wren to turn back, Callahan landed her E-wing further down the road on Lothal to act as a blockade. As Wren continued speeding towards her, Callahan grew increasingly panicked and eventually left her E-wing's cockpit in fear. The Mandalorian managed to avoid Callahan's E-wing by ducking under it, continuing towards the city's comm tower.
Callahan was a female of the human species. She was initially confident that the sight of two New Republic E-wings would deter Sabine Wren and make her return to Lothal's capital. However, Callahan soon abandoned her starfighter in fear for her life when it seemed Wren would crash into it.
Callahan's first appearance was in the first episode of the Disney+ series Ahsoka, which was released on August 22, 2023. Michele Weaver played Callahan.