The disappearance of someone in your dream with your child is an indication that things will go well unexpectedly, such as your worries being resolved by itself or someone appearing to solve them. If he had been putting his work on hold or agonizing over some issues, he could now push ahead with the work in a carefree manner. In other words, it is a dream that obstacles and anxieties, which are symbolized as children, will disappear with help or some kind of opportunity.