Photo source: http://www-history.mcs.st-and.ac.uk/PictDisplay/Kramer.html
A second thanks to Ahmed Umer Ashraf, who suggested posts for Marta Sved and Edna Kramer. Ahmed wrote
I wanted to point out two women in mathematics that were active in their 60s. Marta Sved (I think she was a Hungarian mathematician who flew to Australia) and Edna Kramer (She was a historian of mathematics and wrote The Nature and Growth of Modern Mathematics during her 60s http://en.wikipedia.org/wiki/Edna_Kramer). I know the first as I read her papers and the second because of her excellent book.
There’s a nice biography of Kramer on the biographies of women mathematicians site by by Jennifer Long, Class of 2000 (Agnes Scott College).
Grandma Got STEM 