http://en.wikipedia.org/wiki/Gabrielle_Petit

Petit was born on 20 February 1893 in Tournai to working class parents. She was raised in a Catholic boarding school in Brugelette following her mother's early death. At the outbreak of the First World War, she was living Brussels as a saleswoman. She immediately volunteered to serve with the Belgian Red Cross.[1]

Petit's espionage activities began in 1914, when she helped her wounded soldier fiancé, Maurice Gobert, cross the border into the Netherlands to be reunited with his regiment.[2] She passed along to British Intelligence information about the German army acquired during the trip. They soon hired her, gave her brief training, and sent her to spy on the Imperial German Army. She proceeded to collect information about enemy troop movements using a number of false identities.[2] She was also an active distributor of the clandestine newspaper La Libre Belgique and assisted the underground mail service "Mot du Soldat". She helped several young men across the Dutch border.[1]

Petit was betrayed by a German who presented himself as Dutch and arrested by the German military in February 1916. She was tried and convicted for espionage, with a death sentence imposed on the following 1 March. During her trial, Petit refused to reveal the identities of her fellow agents, despite offers of full amnesty.[1]

Petit was imprisoned at St. Gilles Prison in Brussels. On 1 April 1916 she was shot by a firing squad at the execution field in Schaarbeek. Her body was buried on the grounds there