Her husband was the wealthy advertising executive Ned Crane, and throughout their marriage Frances regularly published articles in The New Yorker, where she became known for her dry, sophisticated sense of humour. She had an extended stay in Germany towards the end of the thirties, but her liberal opinions and outspokenness soon put her at odds with the rising tide of Nazism; she was once reprimanded after thumbing her nose at a speech by Hitler being broadcast over loudspeakers, and on another occasion tried convincing the staff at an anti-Semitic restaurant that she was Jewish (her family were in fact descended from Scottish Presbyterians). She was expelled from Germany following the arrest of her Jewish housekeeper and the woman's son, supposedly for 'crimes against the state', and Frances's subsequent furious articles decrying the Nazi regime.
After leaving behind Nazi Germany, having been recently divorced and faced with mounting college bills from her only daughter, Nancy, Frances began formulating detective stories, upon realising that her old fiction - gentle satires of English culture - were going out of fashion among modern American readers, who were now supporting the British in World War II. Nancy herself was a sculptor and also wrote articles of her own in the late 1940's; she was married to the pulp magazine writer Norbert Davis until his suicide, possibly as a result of his cancer diagnosis, and had one daughter by him, Diana Farris. Frances published no novels in 1949 because of Nancy's near fatal car accident; she crashed the same vehicle her husband gassed himself in, and was left facially mutilated for several months afterwards. Amazingly she had another child, Cynthia, soon after the incident.
Frances published her first crime novel, The Turquoise Shop, in 1941, after hearing about a real-life incident in a jeweller's shop, and subsequently produced 25 more mystery novels, taking early retirement by 1968. She died in an Albuquerque nursing home, where she had spent the previous few months because of ill-health. Her ashes were scattered across her home town of Lawrenceville.