[Vampyr]

This is the wrong question.

No, it isn't alright to hit a female. What we should be far more disturbed by is how okay society is, or even approves of, a female hitting a male.

But to answer the question asked: yes, if she's actually a threat to you, otherwise restrain her or disarm her and take the weapon for yourself. That's the same response I would give if it were a male attacking you.