For all the millions of men (and a few women) in uniform in World War II, there were legions of people working to defeat the Axis powers far away from the battlefields.
Those include thousands of women with above-average skills at mathematics, working to break the codes of the other side. Because they were grown women and it was the 1940s, they were called "girls."
And their story is told in Liza Mundy's book Code Girls: The Untold Story of the American Women Code Breakers of World War II.
We get an overview of the work and the diligent workers in this interview from 2017.