This is Lucy posting under Phil’s log in.
I started Shotokan Karate as a 10 year old and kept training for 15 years. It was one of the best things I did as a child to build my confidence and self discipline. We were lucky enough to be taught by Japanese instructors on a regular basis and our instructors regularly travelled to Japan to train. I was lucky enough to go there once too. We were taught to avoid violence and walk away from confrontation. However on a couple of occasions as a teenager in difficult situations I did call on the skills I had learned for self defense.
If you find a club which offers a range of classes and has a good mix of ages, sex and grades this is a good sign.
I would definitely recommend Karate, if not Judo is great for kids as like the others say it is very good for learning to fall.
Try these people for a club in your area. Their website is being updated but all the links work. Hope this helps.