1) The Prince and the Pauper
I know that Disney had made this starring Mickey Mouse, if there was a Princess version of it. It would be a good idea, the story setting will set in either South Korea oder Japan.
The story will be 100% faithful towards its original story Von Mark Twain.
2) The Man in the Iron Mask
I Liebe this story very much, since watching the 1998 version with Leonardo Di Caprio in it. They will base it on the 1998 version, with the exception that the evil twin redeems himself in the end. Making the first twin princesses to become 2 queens and will rule the country with Liebe and peace, making them the 2 beloved Queens.
Conclusion
Since I only have 2 suggestions as listed, if there are anymore suggestions. Please feel free to add Mehr in the comments.