Jarrilyn was an operative working on Darkside, a repair station in the Cularin asteroid belt. She was also a member of The Cell, a criminal faction wanting to oust and replace local crimelord Nirama. She wasn't very highly placed in the Cell, neither was the Darkside faction in the general Cell scheme.
Jarrilyn was one of the few remaining members of the Darkside contingent after a raid committed by Nirama's forces in 32 BBY. Jarrilyn became a sort of spokesperson for the remaining members, including Ahlya, Dor Balse, Kruss Gaal, Jasper and Michael. At that point, they were trying to recruit new members, including local Wookiees, Kaarl the Ithorian and some newcomers, but the people in Darkside felt no respect for the local Cell. Shortly thereafter, they were captured by a group of spies working for Nirama.
Her implication in The Cell and subsequent capture were public knowledge less than one month later.
At the time of her involvement in the Cell, Jarrilyn was in her middle years, but was still considered pretty, and had dirty blonde hair that she wore in a ponytail.