Jenson began her career in the film business in the early 1980s. Starting out with Hannah Barbara drawing backgrounds for many of the popular cartoon series, she moved onto creating storyboards for both animated and live action.
In the early '90s, she moved studios and worked on the animated feature Ferngully: The Last Rainforest. The film marked her art directorial debut and allowed her to use her storyboard experience in the early stages. With that project complete she moved onto an animated series, Beethoven, which lasted a single season.
In 1996 she moved studios again, this time working as the production designer for the animated musical feature, The Road to El Dorado. The following year, she directed her first animated film, Shrek, with fellow director Adam Adamson. Her first live action film was Post Grad (2009), starring Alexis Bledel.