Lynda Brine's article on sex education does indeed perform "a valuable service", as you say in your leader.
I am a Year 10 tutor and I share her concerns. She highlights the bizarre situation where at a crucial stage a school's input about the most profound experience a human being can have is reduced to the message: avoid disease, avoid babies.
Your editorial goes on to add that teachers cannot assume that "their own morality rules". This implies that there is, somehow, a neutral position.
This is simply not the case.
Either one teaches about sexual relations in the context of the importance of trust and responsibility, or one doesn't. If one doesn't, the absence of such a context implies that these values are not important.