Kretschmann was born in Wrocław, Lower Silesian Voivodeship, Poland (then Breslau, German Empire), on 3 December 1909. As a young woman, she joined an athletics club where she met her future husband, Werner. The two were married and had a daughter.
Following the start of World War II, Kretschmann fled westward with their daughter, while her husband was sent to France as a soldier. The couple reunited with the assistance of the Red Cross after the war’s end; they settled in Stuttgart.
Kretschmann outlived her only daughter. As a centenarian, she continued living independently until 2014, when she moved into a nursing home after suffering a cerebral hemorrhage. At the age of 113, she still enjoyed reading newspapers, sipping a glass of red wine with her meals, and had a fondness for chocolate. When asked about the secret of her longevity, she stated, “It was the sports, the exercise even in winter,” and added, “But certainly also my happy childhood.”
Krestchmann died on 27 August 2024 at the age of 114 years, 268 days.
Kretschmann became the longevity recordholder of Baden-Württemberg in April 2022 after surpassing the final age of Edelgard Huber von Gersdorff.
On 18 September 2022, following the death of 113-year-old Anna Cernohorsky, Kretschmann became the oldest living person in Germany.
Upon the death of Maria Aulenbacher of South Carolina, USA on 8 February 2023, Kretschmann became the oldest living German person in the world.
Kretschmann surpassed the final age of Josefine Ollmann on 8 August 2023, becoming the oldest woman who ever lived in Germany.