Thanks for your concern. I have worked in the travel/education industry for decades and can assue you that I am aware of any safeguarding issues. My daughters would not leave their mother on the landside unless she was 100% sure I was waiting airside for them. And if necessary we would arrange a chapperone but I do not see it being a risk for them just to go through security and passport control unaccompanied as these areas are heavinly policed and secure. Many airlines still accept minors as young as 12 unaccompanied and with chapperones, I have known children as uoung as 8 to travel alone although I do not agree with this.