Regine Ehrenfest-Egger was the sister of Ernst Egger and the daughter of Bela Egger. In 1892 she married the engineer Arthur Ehrenfest (1862–1931) in Vienna. For many years, the Egger and Ehrenfest-Egger families were associated with the Technisches Museum Wien. Until his death, Arthur Ehrenfest-Egger was a member of the advisory board of the Österreichisches Forschungsinstitut für Geschichte der Technik (Austrian Research Institute for the History of Technology) and in this function gave the museum several objects. The couple lived at Mommsengasse 25 in Vienna's 4th district. Their son Fritz Ehrenfest-Egger lived with his parents until his flight to London on 18 August 1939. Regine Ehrenfest-Egger's brother Ernst Egger was also registered at this address. Although baptized a Protestant, Regine Ehrenfest-Egger was considered a Jew under the Nuremburg Laws and as such was required in 1938 to declare her assets to the Vermögensverkehrsstelle (Property Transaction Office). On her behalf, her brother Ernst Egger donated a wireless, an Edison phonograph and a steam indicator to the museum in November 1941. Regine lived in her apartment in Mommsengasse until early 1944. Until then she had not been registered as a Jew by the Council of Elders of the Vienna Jewish Community. She was forced out of her apartment on 6 May 1944 and lived in a "Sammelwohnung" (collective apartment) at Malzgasse 7 in the 2nd district until her deportation to Theresienstadt ghetto on 28 June 1944 on transport XLVIII c/167. She died in Theresienstadt on 9 February 1945.
In 2008 objects were restituted to her heirs following the recommendation in 2007 by the Art Restitution Advisory Board. The Technisches Museum purchased the steam indicator and wireless after they had been restituted, but the Edison phonograph has not yet been found in the depot following the general inventory of the museum.