From my experiences and talking to other moms in real life...both those were struggling and those who had succeeded...
If you have weight to lose, then lose it first (or at least a majority of it) and THEN focus on toning. I don't think it has to be a 100% cardio and 0% toning, but definitely get moving on the weight loss before focusing on toning. It is so true you cannot spot reduce, at least in terms of being overweight and just wanting to lose weight in a few areas. Your body shape will determine when and where you will lose weight far more than the type of exercise.
If you are not overweight, just ah...shall we say reshaped? LOL, then I highly recommend Pilates and yoga like the above person suggested. Especially Pilates! Women who had already lost the weight got into shape in amazing time in the classes I took. Those of us who were still losing weight didn't see nearly the same benefits or results in our bodies. It was almost depressing. Yoga, on the other hand, helps everyone, in my humble opinion, in so many ways that I always recommend it.
Actual weight training (gym or functional) is supposed to be really good for weight loss and muscle strength. I have heard mixed reviews on if abs/bellies develop the muscle under the fat and just look bigger versus helping women slim down overall. I suppose it depends on how you tailor the strength work. I don't personally know anyone in real life who has been successful in using weight training to lose the mama belly.
Best wishes in whatever you decide!
