Charlene's material-mindedness contrasts with the social concerns of her older brother, Robbie. However, over the course of the series, she gradually develops a greater appreciation of her family, of serious causes, and of the role of female dinosaurs, and she awakens to the possibility that there's more to life than allowance, popularity, and cute guys. She demonstrated maturity by watching the Baby ("When Food Goes Bad"), and later comes to appreciate her family, despite Earl's denseness and lack of knowledge of his own offspring, after spending time with Henri and Simone Poupon in "Getting to Know You."
Other achievements include performing as part of the Sinclair Sisters for the USO ("Nuts to War"), gaining temporary fame from training the Cavelings ("Charlene and Her Amazing Humans"), and getting hired by WESAYSO as Earl's supervisor ("Working Girl"). She also discovered that the world is round, and not flat, when her muse mistook her for Copernicus in "Charlene's Flat World." Her idea that the world is actually round was proven correct by walking on it in a straight line.
The final episode demonstrated how Charlene "Gimme" Sinclair had progressed from the days when, upon learning of Robbie's likely death, she planned to turn his room into a "memorial walk-in closet" (Episode 223: Leader of the Pack). In "Changing Nature", Charlene champions the cause of Stan, the last Bunch Beetle, after corporate development leads to the extinction of his kind.