Janice first appears when her boss Hugh J. Magnate Jr. is about to have the Dimmsdale Dogwood tree torn down with Tootie chained to it and does nothing but watch as the bulldozers approach Tootie, though not before she puts on music while Magnate gives his speech and corrects his mistake of calling Dimmsdale "Dummsdale", to which Magnate remarks that it doesn't matter the difference, stating that when he is done with the place, he will consider changing its name to "Stickyrichdale", an idea that is immediately met with applauses. However, he is foiled when Timmy Turner wishes for the bulldozers to break down and chainsaws to become ballons, before also letting Magnate know that Chompy, the Mayor's goat, is eating his pants (another wish from Timmy) while being laughed at by the crowd.
For most of the film, Janice doesn't talk as much nor does she express her feelings or opinions about Magnate's ambitious plans. However, when Magnate captures Tootie and Timmy's fairy godparents, holding mostly the latters hostage inside a cage made of glass and torturing them with electrocution while making wishes for personal gain out of them (she even reacts in disgust when Magnate wishes for a muscular chest), Janice finally stands up for herself and expresses her anger over how ridiculous her job is and walks out. After Timmy kisses Tootie, thus saving his godparents' lives (but also causing them to vanish as a sign that he is growing up and has to give them up) and resulting in all of Magnate's wishes being undone, Janice is last seen when Magnate calls her for help in figuring out why the wishing remote doesn't work anymore (yet the reason is obvious). As a final act of revenge, Janice electrocutes him with the remote by pressing the button tightly, making her former boss fall to the ground with an amusing grin, to which Janice hilariously smiles at and replies "Nice.", before leaving the building, finally free of Magnate's dominance over her. At the end, following her predeccesor's admission to a mental hospital for claiming that fairies exist, Janice goes on to become the new CEO of Magnate Power, now an environmentally-friendly enterprise.
