Shortly before the Germans invaded France in August 1914, her father Henri, a recently retired coal mining foreman, opened a grocery store in Loos, close to Lens.

After her father was arrested by the Germans for violating their strict curfew, Émilienne managed to get him released, but he died in December.

Émilienne, only 17 years old, met with them to give soldiers the precise location of the Germans' position in a small, impregnable fort.

[4] Thanks to this information the Scottish soldiers were able to avoid the fort, which reduced the German effectiveness in this area of the battlefield and resulted in only a few casualties.

She was also recognised by the British Army, who awarded her the Military Medal, the Royal Red Cross (first class), and the Venerable Order of Saint John.

[7] An Australian-made movie entitled The Joan of Arc of Loos (1916) also recounted her accomplishments, but it received much criticism for the title's use of such a revered name.

When World War II was declared, Émilienne was living with her husband, Just Evrard, and their two children, Raoul and Roger, in the French commune of Lens.

She was, however, eventually permitted to return home to Lens, where she started to distribute propaganda brochures against Marshal Philippe Pétain and his capitulation.

While there she worked with other famous resistance members, such as Augustin Laurent, André Le Troquer, and Pierre Lambert.