Simplify the following text for a Grade 9 native English-speaking person.
Original: Prince Leonard is married to Her Royal Highness Princess Shirley of Hutt , Dame of the Rose of Sharon ( nÃ e Shirley Butler ) , by whom he has seven adult children , among them is Crown Prince Ian ( born 1947 ) who is the Prime Minister of the Principality , has been designated as Prince Leonard 's eventual successor as `` heir presumptive '' .
Simplified: Prince Leonard is married to Her Royal Highness Princess Shirley of Hutt , Dame of the Rose of Sharon ( nÃ e Shirley Butler ) . They have seven adult children , among them is Crown Prince Ian ( born 1947 ) who is the Prime Minister of the Principality , and is Prince Leonard 's heir apparent .