Jessie is a young woman with brown eyes and medium-length brown hair tied into a ponytail. In Hoshi o Meguru Otome, it is mentioned she is about Aerith's age, and the Final Fantasy VII Remake Ultimania gives her age as 23. She wears a red headband, a blue shirt underneath a metal breastplate, metal pauldrons, brown gloves, knee-length green capris, and armored boots. Her appearance in Final Fantasy VII Remake stays true to her original design, but adds a black mail shirt to the ensemble and turns her shirt into a leotard with black trim and a zipper on her left shoulder.  

Jessie is the technical expert of Avalanche who builds bombs for raids on the mako reactors, following the plans of the original, more militant Avalanche. Despite being the technical expert, Jessie is pained by insecurities, and is quick to blame herself if a mission goes awry.

She is vibrant and animated, and in Final Fantasy VII Remake, it is revealed her passion before joining Avalanche was acting. She abandoned her dream of becoming an actress when her father became ill, and blames the Shinra Electric Power Company for what happened to him, leading to her joining Avalanche. She is fearless when it comes to love, openly showing her feelings for Cloud and flirting with him. As a former aspiring actress, Jessie now uses her talents to hide her flaws and weaknesses behind smiles, trying to portray herself as strong in front of other Avalanche members. She only truly opens herself to Cloud.