Cäcilie Rosenthal married the lawyer Josef Lilienthal from Zurawno, Galicia, in Lemberg (now Lviv) in 1911. They had three children: Sylvia Lilith, Ricarda Antonia Eleonora and Karl René. After moving to Vienna, they lived from 1914 at Lerchenfelderstraße 13 in the 7th district and then from 1934 in a duplex apartment at Obere Augartenstraße 42 in the 2nd district. Apart from other buildings, the couple purchased a villa at Andreas-Hofer-Zeile 23 in Baden in 1925, to which Cäcilie had sole title from 1927. Both the villa in Baden and the Vienna apartment had numerous art objects, which Josef Lilienthal described in 1938 to the Vermögensverkehrsstelle (Property Transaction Office) as "pictures without museum value, a dresser, sculptures, bracket clocks". Cäcilie Lilienthal also listed jewellery and other valuables. The family were persecuted and expelled under the Nazi regime on account of their Jewish origins. While Karl René was able to flee in 1939 to London, and Sylvia and Ricarda to Palestine, Josef Lilienthal died after a serious illness in March 1940 in the apartment in Obere Augartenstraße. Between 1938 and 1940 he and Cäcilie had already sold some of their properties including the villa in Baden, which was acquired by the furniture and antiques dealers Gustav and Karl Baranyi together with their mother Hedwig. After her husband's death, Cäcilie Lilienthal sold objects from her remaining art collection, presumable to finance her planned flight. In several cases Ferdinand Spany is thought to have acted as a broker. In autumn 1941 a case brought by Cäcilie Lilienthal against Karl Baranyi concerning objects claimed by her from the Baden villa ended in an out-of-court settlement in her favour. In spite of firm preparations, she was no longer able to escape. On 17 June 1942 she was deported first to Theresienstadt and then to Auschwitz. The remaining assets and properties in her name were forfeited to the German Reich.

After the Second World War, her children had their mother declared dead as of 8 May 1945. From 1946, Karl René, Sylvia and Ricarda made several restitution claims for their parents' expropriated assets, also against Karl Baranyi and Ferdinand Spany. The real estate was returned by the mid-1950s, and in 1949 two paintings were handed over to Karl René Lilienthal. After 1950 a claim against Spany ended in an out-of-court settlement in favour of Josef and Cäcilie Lilienthal's descendants, who had asserted claims under the first and second Kunst- und Kulturgutbereinigungsgesetz (KKBG I & II) (Art and Cultural Property Settlement Act) to over two hundred items. By 1997 their claims had been recognized in thirty-three cases. One of the paintings restituted under KKBG I was given on permanent loan in 1995 to the Painting Gallery of the Akademie der bildenden Künste in Wien (Academy of Fine Arts in Vienna), which purchased it in 2006.