Never treat children's feelings as unimportant because they are very real and important to them. There is fast growing evidence that repressing emotions creates a predisposition to illness-and it sure keeps counselors busy decades later. Try to make it all right for kids to ask any question. Children have thousands of curiosities and can be remarkably uninhibited, but do your best. Use age-appropriate answers, but be truthful.
Kids are uncanny about sensing if they are being put on.
If serious situations have arisen, such as a major illness or looming divorce, they'll know something is going on. When grownups deny it, they'll get confused and be haunted by their own dire imaginings. Reassure kids that it's not their fault and that they won't be abandoned. Sometimes a child needs to be steered away from inappropriate or hurtful questions, but do it without rancor. Discipline the deed not the doer.