TBH I feel that answering questions as they come up is so important and to be factual is as well. I was shocked to hear about an inappropriate episode in the prep toilets (yes I know) but grateful that we had had some really low key chats about private parts being private and calling the correct anatomical names.
It gave my DD power/control to stop an interaction that could have possibly deteriorated into an inappropriate situation. Kids will be kids and experiment and explore and whilst I don't want mine growing up before their time I really feel my job is to give them info so they can deal with things as they arise - body changes, periods, sex and relationships etc. These things were not really discussed at all when I was a kid and I wonder how I didn't get into trouble (actually not really cos I was a nerd and just wanted to get into the school netball/tennis/swimming teams but can't guarantee that for the DD's).