The article presents the life and activities of Daughter of Charity Augusta Sikorska. Even a short description of her career indicates that she was one of the most outstanding figures during the 350 years of the existence of her Congregation in Poland. In 1864 she became superior of the seminary and novice mistress, in 1891 she was appointed Provincial Assistant (i.e. deputy Visitator), and three years later Visitator. She held this position until 1919. In 1894, the Warsaw province had 293 sisters in 35 communities. After twenty-five years of Sister Augusta's term of office, this number increased to 647 and 116, respectively. For the first time in the history of the Congregation, the Daughters of Mercy learned nursing and thus obtained qualifications to work in a hospital. On the initiative of Sister Augusta, the Central House of the Congregation in Warsaw at 35 Tamka Street was rebuilt and expanded. Her loyalty and dedication saved the Congregation from disintegration when Director Fr. Idzi Radziszewski insisted on a hasty course of reforms. She also managed to lead the Province unscathed through the period of persecution and repression by the Russians in the last decades of the 19th century. Despite restrictions and prohibitions issued by the authorities, she managed to maintain close contacts with the headquarters of the Congregation in Paris. In addition to routine charity and hospital work, during the term of office of Sister Augusta, the Daughters of Charity undertook three special tasks: a group of nurses operated a hospital train during the Russo-Turkish War (1877-1878), another group was sent to the military hospital in Harbin during the Russo-Japanese War 1904-1905, while in Warsaw the sisters took care of wounded soldiers of all nationalities at the Military Hospital of the Cadet Corps.