While in Paris in 1914, war broke out and she joined the French nursing and ambulance services, the Fondation Baye, serving at the Marne, the Somme and Verdun. She helped with 229 operations in 7 days at the battle of Verdun. On one occasion the ambulance in which she was travelling was shelled and she was wounded in the head and leg. She also came under shellfire while working in a French hospital. The strain led to a period of serious illness, but she insisted on returning to duty once she recovered.