Having only read the first of the three stories so far (as the first one was too good and I'd like to space them out) I can say you'll enjoy this story if you make it through the slow opening chapters. It only gets better the farther you go and the more items come back into play.
The story is set in Magical America where you'd think without Voldemort everything would be ok. This is however not the case as the government seems just as corrupt as in Britain and the social ladder just has a different way of being placed. Like Britain Muggleborns are looked down upon, but in this case they are given separate classes rather than the same and told to catch up. A lot of the conflict of the first book is spent dealing with the differences between Muggleborns and the rest of the school.
The rest is dealing with the fact that Alexandra isn't sure who her father is and really wants to know. Plus she won't let anyone get in her way. Really well done and the titular character seems to grow a lot more than Harry did in the first book.