Hergert Marostegan was born in Limeira, São Paulo, Brazil, on 6 February 1901 to German father and Brazilian mother (daughter of German parents). She had seven brothers and six sisters.
On 17 September 1921, she married Otto João Henrique Hornhardt. The couple had three children: Otto Ricardo, Ademar Emílio, and Bruno Octavio. After eight years of marriage, she was widowed when her husband died of typhus at the age of 28. On 27 January 1941, she married for the second time, to Arnaldo Marostegan, with whom she had her fourth child, Célio Luiz Marostegan.
When asked about her secret to a long life, she said: a simple and happy life.
Hergert Marostegan never visited Germany, her father’s land, as she stated that she felt patriotic towards her homeland Brazil, especially Limeira.
At the time of her 100th birthday, she had 12 grandchildren, 20 great-grandchildren and six great-great-grandchildren.
Hergert Marostegan died on 13 March 2009 in Limeira, São Paulo, Brazil, at the age of 108.
Her age was verified by James Roberts and Stefan Maglov, and validated by Latin American Supercentenarians (LAS) on 12 December 2022, and recognized by LongeviQuest later.