The talented youngster could next be seen as the kidnapped asthmatic daughter of a Charlize Theron and Stuart Townsend in the thriller "Trapped" and played the young version of Reese Witherspoon's character in the romantic comedy "Sweet Home Alabama" (both 2002). Fanning earned kudos for her next leading role, playing a spoiled but ignored young girl with an obsessive distaste for germs who growns up when she's put in the charge of a hard-partying rock star's daughter (Brittany Murphy), who also learns how to mature in "Uptown Girls" (2003). And again Fanning's eerily adult qualities made her an ideal fit for the role of another uptight, control freak young girl, sister Sally in the live-action adaptation of "Dr. Seuss' The Cat in the Hat" (2003)--along with co-star Spencer Breslin, her performance almost redeemed the hyperactive, disappointing film. The pint-sized actress scored another major hit when she appeared in the action-packed revenge drama "Man on Fire" (2004) playing a ten-year-old who befriends her bodyguard (Denzel Washington), prompting him to embark on a deadly journey of retribution when she is kidnapped.

Next Fanning earned reviews that equaled or bettered her co-star Robert DeNiro's when she played a child traumatized by the loss of her mother who seeks solace with an imaginary friend, one who may be a not-so-imaginary source of evil, in the thriller "Hide and Seek" (2005). And she was front and center in one of 2005's biggest summer releases, Steven Spielberg's riveting remake of the sci-fi classic "War of the Worlds," playing Rachel, the wide-eyed daughter of a deadbeat dad (Tom Cruise), who must step up to protect his children during a horrific alien invasion. After voicing the animated character Lilo in the direct-to-video sequel "Lilo and Stitch 2: Stich Has a Glitch" (2005), Fanning starred opposite Kurt Russell in "Dreamer: Inspired By a True Story" (2005) as a young girl whose faith and determination help her father, a once-gifted horse trainer, train a lame mare to compete in the Breeders' Cup Classic. She was then part of a strong ensemble cast in Rodrigo Garcia’s “Nine Lives” (2005), an episodic drama centered around nine different women thematically connected through their various travails. Fanning played the precocious daughter of a widow (Glenn Close) who brings her to picnic at a cemetery where members of their family are buried.