During World War II, Irena Sendler worked for a unit of the Polish underground, Zegota, which was formed to help Jewish children in hiding. As a health worker, Sendler had access to the Warsaw Ghetto. In 1942 and 1943, she led some 2,500 children—twice as many people as Oskar Schindler—out of the ghetto to safe hiding places, the Jewish Virtual Library explains.
Dubbed the “Female Schindler,” Sendler saved babies and children while wearing a Star of David armband to show solidarity with her Jewish protectorates, wrote the Daily Telegraph in its obituary of Sendler. She was technically a welfare worker, distributing medicine and supplies in the Warsaw Ghetto, but she simultaneously “formulated extraordinary schemes to spirit children to safety,” according to the Daily Telegraph.
You can read more about Irena here.Also here is the story of Life in a Jar:
Students from rural Kansas discover a Catholic woman who saved Jewish children. Few had heard of Irena Sendlerowa in 1999. Now after 250 presentations of Life in a Jar, a web site with huge usage and world-wide media attention, Irena is known to the world. How did this beautiful story develop? Read below for the answers.
In the fall of 1999, a rural Kansas teacher encouraged four students to work on a year-long National History Day project which would, among other things, extend the boundaries of the classroom to families in the community, contribute to history learning, teach respect and tolerance, and meet our classroom motto, “He who changes one person, changes the world entire.”
Three ninth graders, Megan Stewart, Elizabeth Cambers, and Jessica Shelton, and an eleventh grader, Sabrina Coons, accepted the challenge and decided to enter their project in the National History Day program (Eventually a number of other male and female students were added to the project). The teacher showed them a short clipping from a March 1994 issue of News and World Report, which said, "Irena Sendler saved 2,500 children from the Warsaw Ghetto in 1942-43." He told the girls the article might be a typographical error, since he had not heard of this woman or story. The students began their research and looked for primary and secondary sources throughout the year.