Is there a legal age to leave a child home alone? "Instead, the law focuses on whether a child is left in circumstances that place them at risk of harm. Instead of basing their decision on the child reaching a certain age, parents should focus on whether it is safe and appropriate for that particular child. Another common question during the school holidays is whether an older child can supervise younger siblings. "Doing so not only reduces the risk of legal consequences but, more importantly, provides children with the supervision, support and reassurance they need during the school holidays."