Protection That Ends in Marriage

Alexandra Henner is a normal everyday girl, not. Her parents are queen and king. Her older sister, Katie is going to take their place along side her husband, Josh whenever it's time for her parents to step down.
Alexandra, who likes to be called Alex and only Alex thinks that everything's perfectly normal. Her mother and father decide to go on vacation, without Alex. Meaning that Alex will be left at home, completely alone.
Alex soon figures out her parents aren't going on vacation, and they aren't coming back for Alex soon. She also finds out she isn't staying in her normal castle-like house all alone, or at all for that matter.