Any parent who is honest knows their child leaps ahead in spurts! At one point around 8 or 9 my son asked about babies being born. Not interested in the sex thing... wanted to know about being a doctor. That phase lasted about 2 days.
I was proactive from toddler years about differences between boys and girls, old and young, and such.
Being open and honest is what's important.
Indeed @madlila. Honesty will ALWAYS be the best policy :):) Thank you for your comment :)