User blog comment:Ginnyharry4ever/Royal Family of the Pridelands/@comment-31583911-20170704171724/@comment-3562042-20170704184511

When Kopa was born, he was naturally this heir, however, on the day of Kiara's birth, Kopa was abducted by the hyenas, and Kiara was proclaimed the heir. When Kion was born, he was proclaimed the second born.

Kopa returned to his family a few months after Kion's birth, but Simba decided to allow Kiara to retain her position as his heir for two reasons
 * it's technically her birthright


 * Kiara understands the pressures, joys, and responsibilities of ruling better then Kopa does