It was fomented into Irena a sense of Justice and equality among all people. Her father Stanislaw died of Typhoid while attending patents whom other doctors refused to attend. (i.e...Jews, Roma, etc...). For this action the Jewish community offered to pay for Irena's education.
At university she spoke up against the practice of the ghetto-bench system that existed at some prewar Polish universities and as a result she was suspended from Warsaw University for three years. But her greatest work was yet to come.
From Wikipedia:Today there are 10's of thousands of people alive today who would not be if Irena and her Żegota resistance members did not save those children.
In August 1943, Żegota (the Council to Aid Jews) nominated Sendler (known by her nom de guerre: Jolanta) to head its children's section. As an employee of the Social Welfare Department, she had a special permit to enter the Warsaw Ghetto to check for signs of typhus, something the Nazis feared would spread beyond the Ghetto. During these visits, she wore a Star of David as a sign of solidarity with the Jewish people and so as not to call attention to herself.
She cooperated with others in Warsaw's Municipal Social Services department, and the RGO (Central Welfare Council), a Polish relief organization that was tolerated under German supervision. She and her co-workers organized the smuggling of Jewish children out of the Ghetto. Under the pretext of conducting inspections of sanitary conditions during a typhus outbreak, Sendler and her co-workers visited the Ghetto and smuggled out babies and small children in ambulances and trams, sometimes disguising them as packages.
Children were placed with Polish families, the Warsaw orphanage of the Sisters of the Family of Mary, or Roman Catholic convents such as the Little Sister Servants of the Blessed Virgin Mary Conceived Immaculate at Turkowice and Chotomów. Sendler worked closely with Zofia Kossak-Szczucka, a resistance fighter and writer, and with Matylda Getter, a nun and the Mother Provincial of the Franciscan Sisters of the Family of Mary. She rescued about 2,500 Jewish children in different education and care facilities for children in Anin, Białołęka, Chotomów, Międzylesie, Płudy, Sejny, Wilno, and other places. Some children were smuggled to priests in parish rectories. She and her co-workers buried lists of the hidden children in jars in order to keep track of their original and new identities. Żegota assured the children that, when the war was over, they would be returned to Jewish relatives.
In 1943, Sendler was arrested by the Gestapo, severely tortured, and sentenced to death. Żegota saved her by bribing German guards on the way to her execution. She was listed on public bulletin boards as among those executed. For the remainder of the war, she lived in hiding, but continued her work for the Jewish children. After the war, she and her co-workers gathered together all of their records with the names and locations of the hidden Jewish children and gave them to their Żegota colleague Adolf Berman and his staff at the Central Committee of Polish Jews. However, almost all of their parents had been killed at the Treblinka extermination camp or had otherwise gone missing.
Many awards were given to Irena over the years. She was named one of the Polish Righteous Among the Nations by Yad Vashem, Given the Order of the White Eagle, the Jan Karski Award, Order of the Smile and the Audrey Hepburn Humanitarian Award (Posthumously). In 2007 she was nominated for the Nobel Peace Prize but it was awarded to Al Gore for a flawed film on Global Warming.
Irena Sendler passed from this world on 12 May 2008 in the city of Warsaw, Poland at the age of 98. But her work and story lives on.
In 1999, students at a high school in Uniontown, Kansas produced a play based on research into Irena Sendler's life story titled Life in a Jar. It has since been adapted for television as The Courageous Heart of Irena Sendler. Actress Anna Paquin played Sendler. Her story was largely unknown to the world until the students developed The Irena Sendler Project, producing their performance Life in a Jar. This student-produced drama has now been performed over 285 times all across the United States, Canada and Poland. Sendler's message of love and respect has grown through the performances, over 1,500 media stories, a student-developed website with 30,000,000 hits, a national teaching award in Poland and the United States, and an educational foundation, the Lowell Milken Education Center, to make Sendler’s story known to the world.
In the fall of 1999, at Uniontown High School in Bourbon County, Kansas, four students were encouraged to work on a year long National History Day project which would extend the boundaries of the classroom to families in the community, contribute to history learning, teach respect and tolerance, and meet the classroom motto, "He who changes one person, changes the world entire."
Three ninth grade girls, Megan Stewart, Elizabeth Cambers, and Jessica Shelton, and an eleventh grade girl, Sabrina Coons, accepted the challenge and decided to enter their project in the National History Day program. Their teacher showed them a short clipping from a March 1994 issue of U.S. 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.
They discovered that Irena entered the Warsaw Ghetto under the disguise of a non-Jewish social worker and talked Jewish parents and grandparents out of their children, rightly saying that all were going to die in the Ghetto or in death camps. Irena took the children past the Nazi guards, using a variety of methods for escape: putting the sedated children in body bags, putting the sedated children under a seat on the tram car, or helping the children escape through the old courthouse. After removing the children from the ghetto, Irena and her coworkers adopted the children into the homes of Polish families or hid them in convents and orphanages. She made lists of the children's real names and put the lists in jars, then buried the jars in a garden, so that someday she could dig up the jars and find the children to tell them of their true identity.
Read more about this amazing program here. You can find more about the Lowell Milken Center here and here.
While the chances of her becoming a saint in the Catholic Church is slim, to the Jewish people Irena Sendler is a saint of the highest rank.