Isabella Garcia-Shapiro is the sassy and fashionable second-in-command of The Resistance. She is also the leader of the Firestorm Girls branch. ("Phineas and Ferb The Movie: Across the 2nd Dimension")
- It is hinted in Phineas and Ferb The Movie Game: The Dimension of Doooom! that she may have a crush on Phineas.