Female Warriors

[Lalaith]

Burzdol, I'm assuming you mean female warriors in Tolkien rather than just generally!
In the First Age, The People of Haleth were one of the three houses of men that were elf-friends. (The others were the house of Beor and the house of Hador). Haleth was a tough cookie, she led her people in battle and elsewhere, and other women of that house also bore arms.
I also think Beren's mother, Emeldir the Man-Hearted, may have done some fighting.
In the notorious Females in the Fellowship thread, one of our scholars mentioned that in some versions Tolkien had Idril Celebrindal, daughter of Turgon, bearing arms during the fall of Gondolin.
And Galadriel has pointed out, there is of course Eowyn. I don't know about Yavanna, I'd never heard that but maybe others can elaborate.