I'm re-writing a Fantasy-but I don't know about one thing. I thinking of including some chapters into the story which sees from Anne's sister, Annbelle's eyes (who's still in the modern world-its where Anne comes from)-should I do it or would it just confuse people?
It depends. If it benefits the story, moves the plot forward and is well-written, then yes. Really, you're the only one who knows if you should do it. You know the storyline and characters and what you're trying to accomplish better than anyone else. Good luck moving forward.
I just commented on a similar question about changing viewpoints in a story. If you're writing in the 3rd person, by all means go for it. Keep in mind, however, that if the Main Character is in the scene, it should always be from their viewpoint. You could change to the sister's viewpoint if the MC is not in the scene.
@D.T. Roberts Um Annbelle and Anne are in two different worlds (modern world and Ellabur) until the last half pf Chapter 12. Since the two ONLY have each other in the modern world-they're orphans-there parents were soldiers killed in the Afghan War and Anne lives in her sister's apartment until she can afford to get her own (that was the plan before she-Anne ended up in Ellabur).
I have another question wouldn't/doesn't the would-be king or for most of the story is a Prince (but he doesn't know that) need to prove to his future subjects he is the rightful heir?
If it isn't obvious then I would assume so. But really, it's your book, who cares? Make things how you want them to be, that's the whole point of writing. Well, for me, anyways. You can rewrite this small part of the politics, can't you? He's King, and your characters aren't going to question you. . . You're the one who made them! Am I wrong?
You know what I think would be better? If he has his own stakes and motivations for being the heir besides just being the "rightful" one. Maybe there's a policy he wants to create/disband that no one else will do, or maybe he wants to lead a fight against tyranny or something. I really don't like "chosen one" type stuff where one is an automatic heir or action-taker. Make the MC *choose* to fill this role, instead. Just my two cents.
There's already is a villain in the story. And for 50% of the story the real heir doesn't even know who he is (he just thinks he's a commoner.