In an early version of the story, Cosmo would've been one of the rangers of the Junior Zap Patrol in a scene where Izzy, Mo and Darby captured Buzz, who was exploring in their secret bunker after an encounter with a robot hound, and demanding to know why he's here when she suddenly comes in, excited to see him and tells him that she wrote a paper in sixth grade called Buzz Lightyear: Traitor of the Century, clarifying that he stole a spaceship and sold them out to alien overlords, but the rangers let Buzz stay with them. One deleted scene also shows Buzz and the rangers captured by Sergeants Rubio and Steele of the Star Command rangers and were placed in their brig after they know Buzz and believing that his father, Lawrence Lightyear, was working with the aliens.
Ultimately, she was cut from the movie altogether due to time constraints.