I agree with you. It seems that they have been doing this for generations. Who knows?
Generations they're definitely cursed because of this damn tradition by now
I agree with you as well! Who knows if we will get answers as of why this happened to Carlyn. Is the ruler really a man? or is it a woman portraying a man as before mentioned by @Herewescreamsilently. Possibly it is a man but because the prince was born a girl, out of shame the ruler just simply had Carlyn live her life as a man and forced to do so in order to satisfy the majesty by gaining what he wanted in the end, even more power by having Carlyn marry the successor of the small kingdom that Mave is from. There's so many possabilities.
I feel like the prince's parent could have been through the exact same thing as the prince, except they never found a way out. The majesty might be a woman presenting as a man