Children who have a narcissistic parent are taught / programmed to believe that they have no rights. They learn that their feelings are wrong, invalid & unimportant. Therefore, the child hides their feelings out of fear of the parent's wrath.
Children of Narcissistic parents are perfect sources of supply. They are no better thought of, they come in handy when supply is scarce and just like everyone in close proximity to the Narcissist, they are idealized, manipulated and stonewalled when.