I just came across what for me was a first, a stamp of a Rebbetzin in a book. The stamp is that of the famed Rachel Citron, the daughter of the Rogatchover. Note the English portion of the stamp, Rev. Mrs Rachel Citron. Much has been written about Rev. Mrs Citron, and her devotion to publishing her father's writings. Below is a photo of a book of her husband she published, Rabbi Yisrael Aba Citron's chiddushim. The introduction is signed by Rachel Citron, "in a pained and broken heart" בלב כואב ונשבר.
Her husband's death, childless, left her in a complicated halachik position regarding her halitzah. One of the deceased's two brothers was an apostate in Germany, the second was a communist, inaccessible in Soviet Russia. You can read about the ensuing debate about how to get the halitzah done, in Marc B. Shapiro's Between the Yeshiva World and Modern Orthodoxy, pages 95-96. She never ended up remarrying, and was murdered in the Holocaust.
Shortly after the last envelope was mailed, the Nazis deported the Jews from Dvinsk to Breslau where they were all murdered on June 3rd 1942 and lie together in a mass grave. Rebbetzin Rachel Citron was a childless widow, and Rabbi Yisroel Alter Safern-Fuchs was only thirty years old and unmarried at the time they were murdered. They spent the last five years of their lives (1936-1941) working feverishly to publish the invaluable writings of the Rogatchover and his correspondences from rabbis in all continents