Perhaps her finest achievement in service to others was nursing soldiers during World War I, first at Leslie House, a wing of which she converted into a hospital for troops invalided out of the conflict, and then at the Coulter Hospital in London. There she nursed her own husband after he was wounded in battle in 1916. She found the work fulfilling and stayed on for two years. During her time with the Coulter Hospital, Noël helped produce the Hurlingham Fete, Fair and Sports, benefiting wounded soldiers, in 1918.