Deciding if your tween or teen is ready to be left home alone can be a tricky decision. A tween is a boy or girl aged 8 to 12 and a teen aged 13-19. We at Kidtection focus on 8-16 ages a tween or a teen. We believe that third adult in the house (aside from the parents is a vital person) especially in long school holidays and after school. However, home alone there is much to consider, we would never consider leaving an under 16 year old alone for a whole weekend (unless adults popping in) at least.