Lerchenthal was born in Munich, Germany, on 8 June 1913. In 1931, after completing high school, she emigrated to Italy and graduated from university in Rome.
Lerchenthal worked as a university professor in Rome, and married a man surnamed Serra Borneto. Her son also achieved a doctorate.
At the age of 110, Lerchenthal still lives in Rome, and is among the top 20 oldest residents of Italy. She is the third-oldest German emigrant in the world after Ilse Meingast, 111, and Dorothea Duisberg, 110.
Lerchenthal has not been reported in the media; she was confirmed privately to have attained supercentenarian status in June 2023.