Knives are good for women who are ALREADY good with the other forms of self-defense.
I highly recommend that you be great with speaking up, whistles, reporting incidents, and mace / pepper spray before getting a knife or a gun. If you are prone to fear and NOT VERY CONFIDENT or STRONG WILLED, having a weapon like a knife or gun can make an act of violence more painful or lethal. The tool can also be used AGAINST YOU if you are not fully capable of handing it.
Using a knife requires more courage and focus.
A knife is also easy to carry and legal.
