What would happen if Harry Potter wasn't born as a boy, but instead a girl? And would what we know of the first book change if it was Severus Snape that came to fetch the cute little girl instead of Hagrid? Definitively! Especially if even the snarky Slytherin can't help but find Arielle Potter cute.
Harry James Potter lives his not-so-normal life at the Dursleys, and survives with the letters that are sent to him every year. And finally, he gets to leave the Dursleys in his Guardian Angel's arms, never to return.
What if there were two Dimensions? One was ours and the other was Harry Potter. What if Remus Lupin sent his daughter to our dimension and she found her way back, knowing all the details from the Harry Potter books.