“Teach your kids martial arts self-defense.”
Don’t learn a sparring-based martial art: Learn to take someone out - death or incapacitation - within a few seconds. I recommend Tim Larkin’s “Target Focus Training.” No muss/fuss, no fancy moves, no “defense,” no “fighting,” no twenty years of training. Just “get ‘er done.”
My daughter took Tae Kwon Do. At first all the forms looked useless, then he had a bunch of students come at him, and he used the forms one after the other to take them out. Turns out learning the forms is to make fighting second nature, you can react instantly to take out someone coming up from whatever direction and in whatever manner because that move has been burned into your mind.
It’s like learning proper stance, grip and breathing for shooting, not just “pull the trigger.” The extensive training in the basics will save you in an emergency situation.
Forgot, I think we can agree though would be that best case mom’s packing heat. A FReeper mom here said she stopped such an attack on her daughter once by showing the gun and asking why that teen picked that particular day to die. Turns out they get really civil and apologetic in such cases.
Kung fu San Soo or Krav Maga. Both are very practical. I hve experience wit hthe former, but not the latter, but I hear very good things about Krav Maga.