Mathieson is listed in Colombo's Canadian References as Canada’s first independent, commercial, non National Film Board, woman animator.
Subsequently, she partnered with Al Guest and continued to pioneer as the first woman in Canadian animation combining writer, director, and producer.
Subsequently they moved to Hollywood, California where they designed and built a complete motion-control system and produced special effects for numerous commercials and the films Alligator, Any Which Way You Can, Body Heat, and One from the Heart, for which they also produced the logo animation for Francis Ford Coppola's Zoetrope Studios.
Although certified as professors at Mount San Antonio College, they left teaching after a year to produce and direct a trailer section of their script - Emily's Story - Wuthering Heights, as a combination live-action & CGI production.
A ground-breaking animated series originating in California and produced in China, it was a hit running Prime Time on the Chinese network CCTV, where, as one of the most popular programs ever aired, it reached an audience of 140 million viewers during its broadcast in 2004.
They also trained Chinese concept, storyboard, and background artists in contemporary American animation style, procedures and technical standards.
Jean Mathieson now works in the Videogame industry where she is credited as Jean Guest on Ratchet & Clank: Size Matters, Secret Agent Clank, Jak and Daxter: The Lost Frontier, DreamWorks Super Star Kartz, Phineas and Ferb the Movie: Across the 2nd Dimension, and "Disney Princess: My Fairytale Adventure".