The martial arts school where we study taekwondo has recently started offering judo and aikido classes for children. (Previously these styles were only offered to adults.) Both of my sons started judo about a month ago and Petunia starts aikido next week--all in addition to the taekwondo, not as a replacement. The boys absolutely love the physicality of judo, all the flips and rolls and falls, and if Petunia becomes reasonably competent at both taekwondo and aikido she'll be able to handle just about anything she might ever need to handle, so I'm all for her studying both. Three styles is a lot for one family at one time, especially with all the other stuff we have going on, but the nice thing about martial arts is that it is not a race. If you have a busy period, you can focus on other things and it will still be there when you have more time to get back to it. And thank all the gods for that, too, since this spring is going to be a scheduling nightmare of epic proportions! Travel soccer. Rec soccer. Baseball. Martial arts. Piano. Yikes, yikes and double yikes.
Oh, and because I've apparently completely taken leave of my senses, I think I may try aikido as well. It's supposed to be great for balance and focus, and it looks really badass. Love the idea of using an attacker's weight and momentum against them with minimal effort, too. We'll see how it goes!