From a Freudian perspective, I think it's a bad idea for a woman to wield a sword. As far as practicality goes, if she wants or needs to carry a blade I'm not going to be the one to stop her. However, women and swords make an uneasy combination if you are planning on objectifying both for the purposes of cheap thrills.
I rotoscoped a composite image to create this fake lady ninja. It's going to be a very small part in a larger piece I will finish later.