If you're not training your legs you have a problem. It's like building a house without a solid foundation. If you do weight training for your legs you'll gain overall strength and power. You'll burn more fat because the legs are such a big muscle group. They require a lot of energy to work. "But I don't want huge thighs", she says. Then train them the right way and, oh yeah, don't stuff yourself when you're done. Resist the urge to eat a lot. Doing legs will increase your appetite a bit because they are such a big muscle group. Have a small protien shake when your done.
So don't forget to do your legs! Build a strong foundation!