[1] In 1901 Maria Antonina entered the Congregation of School Sisters of Notre Dame, a worldwide Roman Catholic order devoted to providing primary, secondary, and post-secondary education.

Ten years before the rebirth of sovereign Poland Kratochwil was sent to Karviná near Cieszyn to teach at a Polish elementary school,[5] twice: between 1906–09, and 1910–17.

[1] Following the Soviet invasion of Poland at the beginning of World War II, the NKVD authorities closed down the Polish schools in Lwów and dismissed the sisters.

[5] Sister Kratochwil intervened against the brutal treatment of Jewish female prisoners by the Gestapo office run by the notorious Holocaust perpetrator SS-Hauptsturmführer Hans Krueger.

[4] {{quote|Enduring inhumane conditions (hunger, beating, tortures, scoffing) she gave witness to Christian love, faith, and forgiveness; she uplifted her Sisters and lay co-prisoners.