During World War II, Grzegorzewska worked as a nurse, was active in the Polish resistance movement, and taught in Warsaw. She joined Żegota and provided assistance to Jews. When Poland was liberated in 1945, Grzegorzewska reactivated the Special Education Institute and within five years introduced graduate and extramural courses to the curricula. In 1950, during the implementation of Stalinist doctrine in Poland, the school was renamed the State College of Special Education () and a state curricula was introduced. She struggled against the state program, wanting to protect special education and people with disabilities. After the 1956 thaw, the institute regained governmental support and reverted to its initial name. Between 1957 and 1960, was a full professor at the University of Warsaw. Her work in science and for the Polish education system were honored with numerous awards and distinctions.