The leader of the Vienna Circle was Moritz Schlick, who was assassinated by a crazy man in 1936. Authorities showed minimal concern because the Vienna Circle was "so Jewish" - horrible times. The book mentions he married a young American woman who had been studying in Europe, around 1905, Blanche Hardy Schlick. Her name appears a few times in the book but not after her husband's death.
A bit of Google research was interesting. Just by searching Blanche Hardy Schlick you can pull up the Google Elibrary of the Smith Alumnae Quarterly Vol 12-13, giving you a long column about the severe travails being undergone by alumna Blanche and her children, despite her husband's fame. The children were literally starving and failing. She mentions her US estate was tied up by the Alien Property Board of the US, and Google tells us the estate was released in July 1921.
Finally, Google shows there is a Blanche Schlick who died and was buried in Vienna in 21 August 1964, suggesting she lived about 50 years after her marriage which is reasonable. Amazing she would have stayed in Germanic Europe after her husband's murder and with the horrors of the 30s and 40s, having already survived the horrors of the 'Teens as shown in her Smith College letter.
She was apparently from Ashburnham MA (pop 6,000), which is about 50 miles NW of Boston. Some JPEGs follow.