The Mexican Revolution was not fought by men alone. Many women took up arms and went to war as well. This was common in the rebel armies, especially among the soldiers fighting for Emiliano Zapata. These brave women were called "soldaderas" and had many duties besides fighting, including cooking meals and caring for the men while the armies were on the move. Sadly, the vital role of the soldaderas in the Revolution has often been overlooked.
This particular photo is estimated to have been taken sometime in 1913, just as the Revolution flared up again with the death of President Madero.