[William Cloud Hicklin]

There's no room in Tolkien's world - call him "misogynist" if you like - for Warrior She-Elves (largely a very, very recent staple of RPGs, movies, comic books etc, plus ancient legend where, again, they were exceptional (Hippolyta, Atalanta) or divine (Athena, the Valkyries). Eowyn is a Thang precisely because she is completely unique and unexpected; as for female Elves, Tolkien merely says that "at need" they would fight to defend their children and homes. In this then they were not unlike the ancient Teutons, of whom Tacitus expressed as much surprise as his laconic style permitted; most enemy women, when the menfolk were defeated, simply accepted slavery meekly.

But the notion that a female would have been Captain of the Guard, or for that matter a member of the Guard or of any regular military body - was alien to Tolkien's imagination (and real-world experience).

(It's to be noted that in the real world right down to the present day, females were not found in ground-combat arms of the world's militaries until the last few years).