thinking more about Maude (spoilers for Harold & Maude)
Re-watching Harold & Maude last week (for the umpteenth time), I found myself more than ever really interested in Maude's back story. She was probably born around 1892. She had a concentration camp tattoo, which she tried to hide from Harold. As a child, she went to garden parties at the Austrian palace and met the King. She had a history of fighting back against authority and oppression, armed in her youth with her yellow umbrella. She loved a man named Frederique, a serious young university professor who, she says, fighting tears, took a job with the government. Her name, Marjorie "Maude" Chardin, definitely seems French. Chardin could be a Jewish name, but is not exclusive to any one religion, so she may have been sent to the camps for being a rabble-rouser.
Based on all that, I think she was probably the daughter of a French ambassador to Austria, and that she stayed on there after her father's post ended. I suspect her relationship with "serious" Frederique was similar to what she had with Harold, that she wanted to save him from his own darkness and teach him to love life, however, in this case, she failed. While she demonstrated against rise of fascism, he joined the fascists, possible even the Nazi Party following the annexation. At the risk of writing melodramatic fan fiction, he may have even turned her into the authorities himself.