Q&A: When is it the appropriate time to talk about private parts with my toddler?
When is a good time to start talking about a child's private areas?
The really short answer to your question is, when your child begins to ask or become curious about them.
You are your child’s most important source of information, especially in the early years. The best explanations don’t evade or shrink from the truth, but set the record straight from the earliest age onward. Still, a 3-, 4-, or even a 10-year-old may not be intellectually or emotionally ready for complicated answers. Being honest, but providing the level of detail that you feel your child can understand is important. If a child is ready for more detail, he or she will usually keep asking questions.
There are many good books available, written for young children, that you and your family may find helpful in addressing topics such as body functions, birth, even grief, and dying. Your public library, or a reasonably large bookstore are good sources.