Found this on the Army Sports site:
http://www.goarmysports.com/gameday/agd/traditions.html
quote:
THE 12th MAN: The 12th man tradition was born in January 1922. Texas A&M was playing Centre College, then the top team in the country. Afraid he might not have enough players to finish the game, Coach Bible remembered that there was a squad man in the press box identifying players. That man, E. King Gill, was a former football player, but that made no difference to Bible, who called Gill down and suited him up just in case.Despite never getting into the game, Gill's willingness to suit up and stand on the sidelines and wait to be called on was admired by all. Said Gill, "I wish I could say that I went in and ran for the winning touchdown, but I did not. I simply stood by in case my team needed me." The spirit of the 12th man standing ready to help the team was soon adopted by the student section and over time the entire student section was dubbed "The 12th Man."At Army, the 12th man collectively refers to the Corps of Cadets in the stands, who, through their passionate cheers and noisemaking, often make it difficult for the opposing team to hear their offensive calls. Typically, the conductor of the pep band paints his face with the number "12" in a combat pattern as it is the pep band that often rallies the corps behind the team.
So they do use it, but she failed to mention that they got it from A&M.
Terrible journalism.