The problem, as I see it, (and you are talking to a woman who did not learn ‘the facts of life’ until she was 15, in biology class, and whose mother was darned upset about it–and no, it wasn’t Catholic school because we had moved and there was no Catholic school available), is that we are polarizing ourselves with two ‘extremes’.
One extreme would have children exposed to ‘sex’ teachings–not to Catholic teachings-- nearly from birth (the public school option. When my children were starting school, 20 years ago now for the oldest, there was a mandatory class about HIV which we were permitted to ‘opt out of’. Problem was, all the other kids attended. Do you think my children DIDN’T find out everything that was said, even though they didn’t want to?)
Another extreme would have individual family autonomy with ‘my right’ to tell my child the sex teaching and (hopefully but not guaranteed) the CATHOLIC teaching when “I” chose. Mrs. A tells her child at age 6, Mrs. B at age 8, Mrs. C at age 10, etc. etc. And of course, this problem means that there is never going to be a time when 'the subject of anything which can be construed as sexual in nature" could EVER be addressed in Church. At any given moment, Father will be faced with at least ONE child in the church whose parents have not ‘given the talk’ and thus, Father will be muzzled eternally.
In one scenario, even though the ‘option to opt out’ exists, the majority of children whose parents opt out–still wind up learning the knowledge, either by fellow classmates or even by ‘sympathetic teachers’ etc.
In the other, theoretically speaking, Catholic teaching about the subject can never be presented in Church lest it impinge on the ‘parental right’.
It’s a puzzle, all right.