I think in this context, the question is about the soldier. Female family members ARE buried at Arlington, as you point out, but with their male veteran spouse/parent. Female soldiers seems to be a recent thing, as they traditionally were confined to noncombat roles.

This article describes an apparent long running dispute on the issue: https://www.cbsnews.com/news/female-wwii-pilots-barred-from-...

And also Arlington didn't become a cemetery until the 1860s, during the Civil War.