The public may know Kate Middleton as the Duchess of Cambridge, but things will change when Prince Charles becomes King of England.

So, what will the world call her when that time comes?

Upon marrying Prince William in 2011, Queen Elizabeth II bestowed the names Duchess of Cambridge, Countess of Strathearn and Lady Carrickfergus on Middleton. However, these titles will be replaced with Princess of Wales when Prince Charles ascends the throne and William becomes Prince of Wales.

According to Cosmopolitan, she will take the role of the late Princess Diana, who used to be the Princess of Wales after marrying the Duke of Cornwall. Though Camilla Bowles might have used that name she chose not to.

Middleton's name will once again change if her husband becomes King. She will become Queen Catherine when it happens, though she can also be called the Queen Consort, which means the partner of the reigning monarch married into the royal family.

However, if William dies, Middleton will have the option to use the name Queen Mother - similar to Queen Elizabeth's mother. Then again, if her son, Prince George, inherits the throne, she can be called HM Queen Catherine, the Queen Mother.

Middleton is mostly called the "Queen-in-waiting," the Daily Express reported Friday. She has been receiving much praise from royal fans all over the world.

"What a wonderful Queen she will make beside Prince William when he is finally crowned King," one fan says. Another shares footage where Middleton is seen laughing while attending an event with a comment "My Queen" alongside. (Business Times)