From the moment the little princess let out her first cry, the young crown prince instantly assumed his new role as an older brother.

On the first night, he stayed with his father, waiting anxiously for his sister’s arrival. The next morning, the first thing he did after waking up was run straight to his mother’s chambers to see his sister.

—Ever since his mother became pregnant with his sister, the little boy had already started sleeping in the adjacent chamber on his own.

When he arrived in his mother’s room, he saw his sister snugly wrapped in her swaddle, …