A good rule of thumb is to treat any member of the royal family as you would if you were meeting your significant other's parents for the first time: avoid controversial topics, keep saucy jokes to yourself, smile and be pleasant, and don't dominate the conversation. People who meet the queen and high-ranking members of the royal family are usually told beforehand that they shouldn't ask the royals direct questions and instead let them guide the conversation. Keep in mind that the royals know protocol better than anyone else, so, if you are in a pinch about what to say, just follow their lead. And, while it may be a natural response, don't say "It's nice to meet you" to the queen — trust us, she knows it's nice to meet her!
