The age difference is 6 years.
The spoiled and arrogant little princess had some secret feelings for her brother, the prince, but she never thought that when she grew up, the prince would marry someone else first. The little princess was so angry that she was bound to kick her sister-in-law out of the position of princess.
But something seemed to go wrong. The grown-up little princess forced the emperor's sister-in-law into a corner and asked through gritted teeth: "You have no feelings for the prince at all, why do you still reject me?"
Intention: Just write whatever you want. If someone sees it, I will continue writing.