Not enough light in those eyes for me. Especially for the little girl.
If you want to "create" dynamic images of kids, you have to make them think your doing something very special and that you need their help. Keep the parents away from them asking them to smile, etc... They just slow things down. The little girls hair is a train wreck. You have to prevent that. If it's windy, have the mother / father tie the hair back. If that's not possible, move to a location out of the wind, or point her into the wind, to keep it out of her face.
But then remember. It really depends on YOUR VISION of the shots your wanting to "create".