https://s-media-cache-ak0.pinimg.com/736x/f0/47/f8/f047f8cf05f2d5d995993aa61b2a062e.jpg

It says, 'Kicking the footpad just below the kneecap is an effective measure of defence'.
I agree; I'd just do it with a chasse bas or coup de pied bas, rather than with the toes (as it seems she's doing in the picture), and then be ready to get away, kick again or hit with the hands.