[6] Braunsteiner was born in Vienna, the youngest of seven children in a strictly observant Roman Catholic family, variously described as petite bourgeoisie (kleinbürgerlich) or working class.

Due to the death of her father in 1934, however, she was required to find employment to support the family and thus unable to enter nursing school.

Braunsteiner worked as a maid, mostly in Vienna, though she briefly moved to live with relatives in the Netherlands for three months in summer 1936.

[7] From 1937 to May 1938, Braunsteiner worked in London for an American engineer's household, but returned to Austria following the Anschluss, fearing possible internment by the British government in the event of war.

[8] Having become a German citizen through the annexation, Braunsteiner filed a request to undergo nurse training with the Blaue Schwesternschaft [de] in Berlin, to no success.

[2][8][7] Unsatisfied with the menial labour, Braunsteiner found out through her landlord, a Fürstenberg police officer, that the recently established Ravensbrück concentration camp had open contractual positions for female supervisors (Aufseherinnen), with a weekly salary of 64 mark, quadruple her current income.

[2] On October 16, 1942, Braunsteiner assumed her duties in the forced-labor apparel factory near the Majdanek concentration camp, established near Lublin, Poland, a year earlier.

Working alongside other female guards such as Elsa Ehrich, Hildegard Lächert, Marta Ulrich, Alice Orlowski, Charlotte Karla Mayer-Woellert, Erna Wallisch and Elisabeth Knoblich, Braunsteiner became known for her wild rages and tantrums.

She noted for her particularly cruel treatment of children, whom she called "useless eaters", regularly punishing them for minor infractions such as wearing stockings and pillows for warmth or incorrectly sewing their identification numbers to clothes, and in one instance, she beat a group of starved children with a ladle for coming too early for food distribution.

[1][12] In January 1944, Braunsteiner was ordered back to Ravensbrück as Majdanek began evacuations due to the approaching front line.

[13] A French physician, who was interned at Genthin recalled the sadism of Braunsteiner while she ruled the camp: "I watched her administer twenty-five lashes with a riding crop to a young Russian girl suspected of having tried sabotage.

She then returned to Vienna,[1] where Austrian police arrested Braunsteiner a year later on May 6, 1946, and turned her over to the British military occupation authorities.

They lived in Maspeth, Queens, New York City, where she was known as a fastidious housewife with a friendly manner, married to a construction worker.

"[15] On August 22, 1968, United States authorities sought to revoke Braunsteiner's citizenship, since she had failed to disclose her convictions for war crimes; she was denaturalized in 1971 after entering into a consent judgment to avoid deportation.

[2][3][23] A prosecutor in Düsseldorf began investigating Braunsteiner's wartime behavior, and in 1973 the West German government requested her extradition, accusing her of joint responsibility in the death of 200,000 people.

[2] During the next year, she sat with her husband in United States district court in Queens, hearing survivors' testimony against the former Schutzstaffel (SS) guard.

[29] One of the witnesses against Braunsteiner testified that she "seized children by their hair and threw them on trucks heading to the gas chambers."

The defendants included Ryan, former SS guard Hermann Hackmann and camp doctor Heinrich Schmidt.

[1][8][30][33] After the publicity surrounding Ryan's extradition, the United States government established in 1979 a U.S. DOJ Office of Special Investigations to seek out war criminals to denaturalize or deport.