Emma Green was born in 1843 in Alexandria, Virginia. Her father, James Green, was the owner of the Mansion House Hotel and the richest man in Alexandria. The family also owned the Green & Brother furniture factory, which was confiscated as a prison for Union deserters.
In November 1861, the family was forced out of the Mansion House Hotel and it was confiscated by the Union Army on December 1, 1861. The Union Army began using the Green family hotel as a First Division General Hospital, and it was the largest of the confiscated buildings used as a military hospital in the city. It could hold up to 700 sick and wounded soldiers.
During the war, her fiancé Benjamin Franklin "Frank" Stringfellow operated as a Confederate spy. It is possible that she assisted in his espionage activities. Enlisting in the Confederate Army at the start of the war, Stringfellow was sent to spy in Alexandria while pretending to be a dental assistant. At one point in April 1862, in the dentist’s office, Emma incidentally encountered him and called him by name. However, suspicions were not raised and they avoided further contact through 1862, while he remained with the dentist. Frank eventually left Alexandria for other missions.
Frank Stringfellow returned to Alexandria in 1863, again as a spy. According to some historians, such as author Virginia Morton, Emma assisted Frank throughout 1863. In one story, "Stringfellow proceeded to Emma’s house alone but discovered Union officers occupying the upper levels. Undeterred, he crept into the cellar from the back of the house and asked Emma’s maid to fetch her… Emma agreed to call on the informers and returned within a few hours with vital information of Union Gen. Irvin McDowell’s planned attack."
Frank Stringfellow returned to Washington in March 1865, and reports say that Emma moved to live with family friends so she could be closer to him. By the end of the War, he had a $10,000 bounty for his capture. When Richmond fell, Frank left for Virginia, after he discovered that he was rumored to be an accomplice in Lincoln's assassination. He eventually made his way to Canada. Following the surrender of the Confederacy on April 9, 1865, the Mansion House was returned to the Greens and reopened as a hotel, operating as the Mansion House Hotel until it was acquired by new proprietors in the early 1880s.
After the war, Emma reunited with Frank when he returned from Canada, and they were married on January 23, 1867. Frank became an Episcopalian minister, and they had four children.
In 1883, the Green family was awarded late rent by the US government for its use of the Mansion House Hotel. Frank Stringfellow died in 1913. Emma lived until 1929. Frank and Emma are buried at Ivy Hill Cemetery in Alexandria.