Belle Boyd and Jackson - Virginia Historical Markers on Waymarking.com

And now for the rest of the story as learned from Wikipedia (see link below):

Belle Boyd's espionage career began by chance. On July 4, 1861, a band of Union army soldiers broke into her home in Martinsburg, intent on raising the U. S. flag over the house. When one of them pushed her mother, Belle drew a pistol and killed him. She was 18 years old. A board of inquiry exonerated her, but sentries were posted around the house and officers kept close track of her activities. She profited from this enforced familiarity, charming at least one of the officers, Capt. Daniel Keily, into revealing military secrets. "To him," she wrote later, "I am indebted for some very remarkable effusions, some withered flowers, and a great deal of important information." Belle conveyed those secrets to Confederate officers via her slave, Eliza Hopewell, who carried the messages in a hollowed-out watch case. On her first attempt at spying she was caught and told she could be sentenced to death, but was not. She was not scared and realized she needed to find a better way to communicate.

Belle Boyd was not blessed with a pretty face, but a good body. She was particularly noted for having the best looking ankles known--and she used them to her advantage. She evidently had a "winning way" with the Union troops and was most obliging in taking care of their needs.

Then, one evening in mid-May 1862, Union General James Shields and his staff gathered in the parlor of the local hotel. Belle hid upstairs, eavesdropping through a knothole in the floor. She learned that Shields had been ordered east, a move that would reduce the Union Army's strength at Front Royal. That night, Belle rode through Union lines, using false papers to bluff her way past the sentries, and reported the news to Col. Turner Ashby, who was scouting for the Confederates. She then returned to town. When the Confederates advanced on Front Royal on May 23, Belle ran to greet General Stonewall Jackson's men, braving enemy fire that put bullet holes in her skirt. She urged an officer to inform Jackson that "the Yankee force is very small. Tell him to charge right down and he will catch them all." Jackson did and that evening penned a note of gratitude to her: "I thank you, for myself and for the army, for the immense service that you have rendered your country today." For her contributions, she was awarded the Southern Cross of Honor. Jackson also gave her captain and honorary aide-de-camp positions.

After her lover gave her up, Belle Boyd was arrested on July 29, 1862, and held for a month in the Old Capitol Prison in Washington before being released. She was later arrested and imprisoned a 3rd time, but again was set free.

In 1864, she went to England where she met and married a Union naval officer, Samuel Wylde Hardinge, who died shortly after the war's end. After the war, Belle Boyd became an actress in England before returning to the United States. She then married John Swainston Hammond (1869) in New Orleans and, after a divorce in 1884, married Nathaniel Rue High (1885). A year later, she began touring the country giving dramatic lectures of her life as a Civil War spy.

While touring the United States (she had gone to address members of a GAR post) she died of typhoid fever in Kilbourne City, Wisconsin (now known as Wisconsin Dells, Wisconsin) at the age of 56. She is buried in the Spring Grove Cemetery in Wisconsin Dells.