It's about a spy who's working for two opposing sides. There's a lot of intrigue and action as they try to balance their loyalties and keep their identities secret.
Perhaps it was through a combination of courage, kindness, and a series of challenges overcome that ultimately led to your becoming the princess in the manhwa. Maybe a mysterious force chose you for this role because of your unique qualities.
It could be through some kind of magical transformation or a hidden heritage revealed. Maybe there was a prophecy or a special event that triggered it.
Often, in such manhwas, the princess becomes the queen due to various factors. It could be because of her noble birthright, her ability to handle political intrigues, or her kindness and wisdom that win the hearts of the people and the support of important allies.