On 29 April 1944, the Hungarian gendarmerie, who worked together with the Eichmann commando, arrested her, her parents Irma and Dezső Fahidi, and her eleven years old sister Gilike, and locked the family with other Jews in the city in a newly built ghetto that served as a prison.

[3] On 14 May 1944, they were deported to the Auschwitz-Birkenau concentration camp where her mother and sister were selected to die in the gas chambers by SS doctor Josef Mengele.

Fahidi was persuaded to go to Germany as a translator, and in October 1990 she took part in a week-long meeting in Stadtallendorf, where local representatives asked the former prisoners for forgiveness.

Thereafter she visited the site regularly, giving lectures and interviews, questioning other contemporary witnesses, and guiding school classes through the memorial.

[13][14] In 2011, Fahidi agreed to testify as a co-plaintiff in the criminal trials against the former concentration camp guards Hans Lipschis and Johann Breyer.

In 1944, both, while in a Sturmbann (roughly "assault group"), had been involved in the murder of Hungarian Jews by the SS-Totenkopf units in Auschwitz-Birkenau, possibly also in the selection of the Fahidi family.

As one of the last survivors of the Shoah, she expressed the hope that the memory of it would be effectively kept alive after her death through books, documents and places of remembrance: "It must not and cannot happen again."