Recently, we had a friend who lost their baby due to a miscarriage. I remember getting off the phone, looking at Tim with all 3 of our children in his lap as he asked, "What happened?" I replied, "They lost the baby," and immediately my 6-year-old's face was scared. I turned away from them to take care of something in the other room only to return five minutes later and overhear Tim praying with our boys, Max softly sobbing on his daddy's shoulder.
A comment I made, meant for and understood immediately by my husband's adult ears, had struck a chord with Max, confusing him, scaring him, and causing him to ask some very grown-up questions of us--questions about death, about God's plans, about "why" our friend's baby died--questions we might not have been ready to discuss with him at his young age, but we had to address and answer, because it was his time.
We've decided that, as parents, we need to be prepared to answer our kid's questions--even the grown-up ones--when they're ready to ask them. The reason behind this is pretty simple: If our 1st or 2nd grader has a question about sex or death or religion, we want to be the ones to answer that question. We don't want to brush them off or say we'll discuss it later, because sooner or later they'll stop coming to us with their questions and they'll head somewhere else to have them answered.
So, my encouragement to you is this: Be ready to be hit with some grown-up questions from your kids, but instead of delaying until the "age-appropriate" time to answer them (whatever that happens to be), be challenged to answer them honestly (and age-appropriately) when they are seeking. Otherwise, the 6th-grader down the street might be the one to tell your kindergartner "what boobs are" or "how babies are made" or "what happens when they die." I don't know about you, but I want my children to know the true answers to those questions...and I want it to come from me.