Bestfriend, Prince, Fiance?

Lady Arabella Ashlynn McKenna, best friend to Prince Chanceon heir to the Genevian throne, since the day they were both born. They grew up together and have always been best friends, even though for each school year she was sent to live with her mothers cousins in America. They always told her it was for her safety, because she was so cared for by the Genevian royals, they never told her it was because she had been betrothed to her best friend since she was just an hour old.