Your children have to be receptive in order to take in information. If they are not, and you share it with them anyway, the information may not sink in or, worse, may cause them cognitive or emotional distress. Untimely sharing of information is a bit like force-feeding. Don’t do it. But don’t avoid hard topics or sugar-coat the truth either. Your child is likely to sense your discomfort and blow the topic out of proportion, imagining the worst.
With kids, if they can formulate a reasonable question on a topic, they are probably ready to accommodate a truthful answer. This does not mean you have to share all of the truth. If they ask where babies come from, you need not broach the topic of deviant sex. If they ask about death, you need not unload your own fears and anxieties, or elaborate on your beliefs about the afterlife. If you do not know where to start with them, simply ask your children “what do you think?” and start there.
Don’t ever foist your own agenda onto a child. This includes both avoiding a topic they are ready to talk about and sharing a truth they are not ready to hear.