Being an au pair to a school-aged child or teenager is a different kind of relationship. Being a mentor, an older sibling, and someone they admire is important. If you are caring for an older child, the truth is they might be more comfortable talking to you than to their host parents when they are struggling with something. To support your host children, and keep them safe, you should know the type of dangers and challenges they might experience.
Some house rules for a teenager might be as simple as when something is allowed. For example, be aware of nighttime routine and when they are allowed to use electronics. A caffeine filled teenager up late playing computer games might be common in the household, but if this is against the rules, it is not allowed.