Breslin was the younger sister of child actor Spencer Breslin, who starred in "Disney's The Kid" (2000) and "The Cat in the Hat" (2003); the siblings appeared together in the 2004 weeper "Raising Helen" and "The Princess Diaries 2: Royal Engagement." Her acting career began with appearances in several national television commercials, starting at the age of three. Her big break came in 2002 when M. Night Shyamalan cast her as Mel Gibson's youngest daughter in his science fiction hit, "Signs." Her character in the film - a curiously grave adolescent girl dealing with the traumatic death of her mother - clearly showed that Breslin had the chops to handle complex parts even at the tender age of six.Turns on episodic series such as "Law and Order: Special Victims Unit" (NBC, 1999-) and "N.C.I.S." (CBS, 2003-) preceded a trio of films in 2004 - all very different in tone and audience. In "Raising Helen," she was one of three recently orphaned children being raised by their career-minded aunt, while in the frothy teen comedy/romance "The Princess Diaries 2: Royal Engagement" (2004), she had what amounted to a cameo as a parade girl. Her final 2004 film was the dark, psychological drama "Keane" by director Lodge Kerrigan, in which she played the young daughter of a down-and-out mother who entrusts her child to a man who appears to be teetering on the edge of madness.More TV and a direct-to-video feature - the kids' movie "Chestnut: Hero of Central Park," (2006) - followed, but "Little Miss Sunshine" was primed and sitting in the wings. Her star-making performance - which stood out in a cast peopled by such top talent as Greg Kinnear, Toni Collette, Steve Carrell, and the esteemed Alan Arkin, with whom she shared some of the film's funniest scenes - was recognized by the Gotham Awards, who nominated her for Breakthrough Performance and as part of the Best Ensemble Cast. She also got a nod from the Screen Actors Guild Awards, earning a nomination for Outstanding Performance by a Female Actor in a Supporting Role - Theatrical Motion Pictures. The ultimate recognition came with an Oscar nod for Best Supporting Actress, making her the fourth-youngest actress ever nominated.Following her triumph in "Sunshine," Breslin was besieged with offers for both film and television. She landed a guest-starring turn on "Grey's Anatomy" (ABC, 2005-) as a child who cannot experience physical pain, and added some zest to the Vince Vaughn holiday comedy "Fred Claus" (2007). In the romantic comedy "No Reservations" (2007), she was again tapped to provide precocious charm as a nine-year-old entrusted to the care of an exacting and ambitious chef (Catherine Zeta-Jones) who has a love/hate relationship with co-worker Aaron Eckhart. The independent romantic comedy "Definitely, Maybe" (2008) fared better with critics, and gave Breslin a little more to work with in her role as the daughter of a divorcé (Ryan Reynolds) who tells her the story of his early romances.Next up for the busy actress, Breslin co-starred alongside former child star Jodie Foster in the family adventure "Nim's Island" (2008), and gave younger audiences another offering with "Kit Kittredge: An American Girl" (2008), based on the popular series of historic dolls and books. Taking a more serious turn, she starred as the sister of a cancer patient (Sofia Vassilieva) who sues over the right to decide whether or not to donate an organ to her sibling in "My Sister's Keeper" (2009). In the fall of that year she returned to comedy, albeit in a gorier setting, with the tongue-in-cheek horror movie "Zombieland" (2009). In 2010, Breslin debuted on Broadway, portraying Helen Keller in a well-received revival of "The Miracle Worker." Back on the screen, she played the title character in the music-oriented dramedy "Janie Jones" (2010), voiced a mouse in the quirky animated adventure "Rango" (2011) and appeared in the ensemble romantic comedy "New Year's Eve" (2011). Two year later, Breslin resurfaced as a young woman in her late teens, starring in the tense thriller "The Call" with Halle Berry, before taking supporting roles in the sci-fi movie "Ender's Game," featuring fellow maturing actor Asa Butterfield, and the ensemble drama "August: Osage County," starring Meryl Streep and Julia Roberts. Direct-to-video thriller "Wicked Blood" (2014) and crime drama "Perfect Sisters" (2014) were followed by the title role in "Maggie" (2015), a post-apocalyptic thriller in which she starred opposite Arnold Schwarzenegger. After starring in togue in cheek teen horror flick "Final Girl" (2015), Breslin joined the cast of Ryan Murphy's campy horror spoof "Scream Queens" (Fox 2015-16). Breslin next starred in Trudie Styler's indie drama "Freak Show" (2017), after which she starred as Frances "Baby" Housman in a musical reboot of 1987 hit "Dirty Dancing" (ABC 2017).