It is at the very least rash to assume that such blanket statements will apply to all individuals. While it may be safe to say that there is a tendency for women to be more nurturing, there are frequent exceptions to that rule, different degrees of expression, and situations where that nurturing is expressed as a protective instinct. My wife is a very kind person who is universally liked, but there is no doubt in my mind that she would have been absolutely fierce if she had been forced to defend our children when they were little. (And no that I think of it, I am not sure I would want to oppose her on those grounds even now that they are adults.)
I also find it very questionable to think that women would have any tendency towards finding an edged weapon to more acceptable than a firearm. My hunch would be that the closeness and intimacy of using a knife would be less acceptable for many women, to a somewhat parallel degree to which they would exhibit the nurturing thoughts above.
I would be really interested to hear Dr. Meyers' thoughts on this subject.