The popular view of Karate practitioners is of bald headed men with no teeth, but this is far from true.
Many women of all ages practise karate and there are many highly skilled and highly regarded female martial artists. This is not a recent phenomenon, Shaolin nuns were practicing the martial arts over a thousand years ago!
The perceived disadvantage that women have is that, in general, a woman will be smaller in stature and not as physically strong as a man. Biologically this is an undeniable fact, but it is not a disadvantage in Karate.
In fact, women have certain advantages over their male counterparts.
Karate was designed to provide an effective way to defend yourself from an aggressor who is larger and more powerful than you and/or armed. Though not designed specifically with women in mind, Karate is a martial art that relies very heavily on skill to overcome brute force. Most men will rely on their physical presence to overpower their victim(s), but a well placed blow at the correct time will stop anyone.
Any idiot can make a fist and lash out wildly using weight and impetus. Karate teaches precision, timing and accuracy to land a single blow which “stops” your attacker with a single blow.