"She's a Rebel" is the eighth song on Green Day's 2004 rock opera album, American Idiot. At one minute and fifty eight seconds, it is also the shortest song on the album and continues the story of the Jesus of Suburbia character, introduced in earlier tracks. It modulates from the previous track's key signature of A down a step to G major. Its chord structure is simplistic even by the standards of punk rock, progressing in an ordinary I-V-IV pattern in power chords (which changes to the equally common I-IV-V in the verse). This song is Whatsername's "introduction" song, much like the songs Jesus of Suburbia and St. Jimmy. However, this song is not written from the point of view of the person it describes. Whatsername's "voice" is later heard in "Extraordinary Girl" and "Letterbomb." The song bears striking similarity to Molly's Lips by The Vaselines (covered by Nirvana).

Whilst on the streets, the Jesus of Suburbia meets a girl known as Whatsername. This results in love at first sight for the main character, who is instantly captivated by the girl. This emotional feeling is conveyed with the lyric "She's holding on my heart like a hand grenade", which is also a reference by Billie Joe Armstrong to the main emblem of the album, a hand holding a heart-shaped hand grenade. There is also a meaning that this song could be about America, as the song is dated on July 4th and the song makes sense if the word "she" is replaced with "America". Or, in another popular interpretation, she could be viewed as the statue of liberty considering the emphasis of the song on symbolic representation. It's also important to note that the song Holiday has a direct link to this song through the lyric dawning of our lives, which implies a strong skeptic view of US politics as it stands. In this case, the rebel is the statue of liberty who will always represent the same rebellion and liberation despite how politics change. This makes her a good symbol for uprising and defiance in the face of popular politics and ideas. The statue may also symbolize running against the grain, as it was originally a gift from the French, who are not fully supported by America currently.