Dagger or sword (not able to wield a bow yet), no matter what my character equips it doesn't show in her hand. She always seems to strike with the fist in combat. Though the shield equips on the sprite all right.

Is it a bug related to the female character, obviously added posteriorly to the game? (It seems originally there was only a male one, since everyone call her "boy" and she's referred to as a brother to her brother.)

Hi,
in order to sheath your sword press spacebar. Furthermore you can press F1 ingame to get an overview about all "hotkeys".

So it has nothing to do with female character.
But besides: In my opinion it was the wrong choice to implement the function of changing the gender of the main character.