The Queen of England is the female monarch of England in the United Kingdom. A woman may become the queen either by being married to the king or being the first born.
When Senator Robert Kelly held a press conference to announce his candidacy for President of the United States of America, Jubilee joked that if he won she was the Queen of England.
Elizabeth II went to New York City along with Charles, Prince of Wales and Diana, Princess of Wales. While there, a Skrull imitating Invisible Woman stole her crown.
Presumably, if Elizabeth died then Charles would become king and his wife Diana would become queen.