The correct formal way to address a Crown Princess is as "Your Royal Highness" upon the first meeting, and subsequently as "Ma'am" (rhymes with "jam"). In written correspondence, she should be formally addressed as "Her Royal Highness the Crown Princess of [Country Name]," and the letter's salutation should begin with "Your Royal Highness." It is important to note that a "Crown Princess" is a specific title for a female heir apparent to a throne (like Crown Princess Victoria of Sweden) or the wife of a Crown Prince. Unlike a regular princess, she holds a senior constitutional rank. When speaking about her in the third person, you would refer to her as "Her Royal Highness." While modern monarchies have become slightly more relaxed, adhering to these traditional forms of address is still considered a sign of respect and protocol during official engagements or formal introductions.