Jackie Kowalski is a Sergeant at the Top 10 precinct. We are introduced to her when Toybox, the precinct's newest recruit meets her. After offering to go out for beers, Jackie reveals to Robyn that she is a lesbian, which doesn't go down too well with her. However, during later discussions with Jeff Smax, and Irma Geddon and Girl One, Robyn defends Jackie.
Jackie works closely with her partner, Peregrine, though their work is sometimes strained by Peregrine's conservative Christian values and Jackie's homosexuality. Nonetheless, they are an effective team, working to apprehend the customer of a murdered prositute, before attempting to solve the Libra case - A murdered who leaves their victims headless. After a lead arises, Jackie leads the assault on Libra, taking Dust Devil and Shock Headed Peter into the sewers to find the killer. Here, she reinforces her playful side, chatting jovially with Dust Devil (who is immensely attracted to her) about the sexiness of monster trucks. Following an encounter with Libra, after which Jackie ends up in her fellow officer's grasp, she makes a crack about Dust Devil's 'hidden derringer'.
Following the subduing and arrest of Libra, revealed to be alien pornstar and former hero M'rglla Qualtz, Jackie later attempts to capture the Ghostly Goose (a superhuman ass grabber), when it touches her rear in a cafe. It is a false lead, though the Goose is later revealed to be hiding in Jackie's chair, in the Top 10 cafeteria.
In a surprising turn, she appears to come onto Jeff Smax, claiming she's only a lesbian by misunderstanding, and proceeds to suggest they should kiss in a big way. However, this is revealed to be a dream on Smax's behalf. Jackie is later revealed to be attracted to Peregrine, which suggests a liking for larger, moderately muscular woman.
Following the chaos of the corrupt Commissioner Ultima's inspection of Top 10 (a cover to obtain a highly powerful drug), Jackie joins Peregrine in apprehending Sun Woman, a member of the famous super-team the Sentinels, after it is revealed the group runs a pedophile grooming operation.
Five years after the Ultima incident, Jackie is in a relationship with her partner, Panthalassa.