Marcelina undertook the work of educating women in the conviction that on it depends the rebirth of the family, which is the foundation of a morally healthy society. Among her principles for the formation of her sisters and students, she stressed the following: the primacy of God over everything, truth, mutual trust and unselfishness. She also offered effective help to the poor, desiring that tuition-free elementary schools be established at every convent. During her 50 years of Superior of the congregation, she opened seven convents with formation institutes and schools for children.
In 1904, the Polish writer Henry Sienkiewicz wrote of her: "Praise for your wise work and honour to your merit and goodness". Marcelina answered, saying: "I don't look at the results of our work. They don't belong to us. If they exist, they belong to God for the good of our beloved country, which is torn apart". She died on 5 January 1911.
On 6 October 1996 Marcelina Darowska was proclaimed Blessed by the Pope John Paul II in Rome. During the Mass he said:
"To extend the kingdom of God in human souls and bring it into the world" - this was the programme for her apostolic activity, born in the silence of a heart immersed in prayer. She wanted to do everything so that truth love and goodness would triumph in human life and transform the face of her beloved nation. Together with her sisters, she generously laboured in the exhausting task of building the kingdom of Christ, paying particular attention to the religious formation of the young generation, especially girls, to the growth of catechesis and to educational work. She assigned a particular role in life to the Christian woman as "wife, mother and citizen of her country". With great zeal she fostered the growth of the kingdom of God in the family, since only a healthy and holy family, "based on God", as she said, can be the foundation of a new society. The new blessed is an example of an apostolic faith that creates new ways for the Church to be present in the world and forms a more just and human society which "abides and bears fruit" in Christ. "
Pope John Paul II, from the proclamation of the beatification of Blessed Marcelina Darowska