The way things are today, girls are not as safe as they used to be when out alone or with other girls. I see many girls in martial arts classes but having been in martial arts off and on for the last 30 years, I know that in real life, too many of them come up deficient and a young woman winds up being no less defenseless than she would be without it.
All of my daughters I have gotten into two things. One is Shaolin Kempo Karate. A very basic, no frills martial art that involves boxing style hand techniques and kick, short, very powerful kicks no higher than the chest. The art works using the techniques in combination. Punch, punch kick. Usually all in one motion. A backfist with the right hand, follow the momentum with a left hook, follow through with a spinning back kick to the chest, stomach or ribs. You land the first one, you will usually land all three. Miss the first one, it will still make him react and you still are following up with the other two. The opponent will still be off balance. If you miss all three you can continue with another technique.
But the main thing that I have gotten my girls into for self defense is weapons. All three of then are proficient knife fighters. They spar constantly at home using magic markers. The problem with this is that if it comes right down to it, a young girl may get squeamish about spilling some deserving fucker's guts. My girls have helped me slaughter calves and goats.
All four of my daughters carry the same model of knife. My oldest one is the one to have ever had to use hers to stop an assault. The guy is lucky to still be alive. She slashed his arm and stabbed at his heart (just like in training). The guy was lucky to have been carrying his cellphone in the inside pocket of his jacket. He backed away, fell, got his head stomped and a knife held against his eye by an absolutely crazy Mexican girl who took his wallet and license so she and her brothers could find him later. I wonder how many days it was before he went home?
I am all for having girls train with knives and carrying them for self defense. But they have to be willing to use it. I am open to any other sugestions.