sentence: This meant that when Princess Victoria of Sweden was born, she could never become queen, and when her younger brother was born he became crown prince (heir to the throne) -- but then the law changed, and Victoria became crown princess.
modified: This meant that when Princess Victoria of Sweden were born, she could never become queen, and when her youngest brothest was born he became crown prince (heir to the throne) -- but then the law changed, and Victoria became crown princess.