the network for radical unschooling families
It seems similar in some regards to giving other kids food - I made sure my kids both knew not to just hand food to other children, to check in with me or the other parent first. Sometimes there are allergies, but often there are other issues, issues of parental control and kids "having to ask". That might be something to talk about with your dd - that other families have different rules and its the parents who decide what kids can learn about.
I remember Phoenix used to spend hours on Howstuffworks.com watching the animations and videos about reproduction, and then one day, he was just over it.