@TyShaye It was already said in previous chapters that it was inflicted by the princess' royal family. That's why it would be natural for the princess to be able to remove the curse (even without having knowledge of how to do so) if the plot followed the original storyline.
That also goes back to why Ibee wanted to keep the fact that she cured it a secret. She has no ties to the other kingdom, so questions would arise as to how a mere maid was able to break an unbreakable curse.
I'm sure we'll see those storylines play out as dramatically as possible in upcoming chapters. At least, I hope so!
@subliminal I didn't even think about that as a possibility. That would be an awesome twist! I mean, we never see her search for information about her past and she clearly gets shunted into the book without any notion of her age or even name, so it's not outside the realm of possibility that she has a deeper past that will come into play soon enough.