The Unknown Potter

James and Lilly Potter had another child. Harry has a younger sibling that he sees in his dream of that night but doesn't know her name or how he knows her. After the attack she was somehow found in the street's of New York by a Chef who took her to the hospital and after finding no records he decided to keep her.
He named her Allison Minnie Vixion.

Disclaimer: I don't own Harry Potter nore do I own any other shows that might pop into this story. I apologize if I somehow offend anyone when their character is not who they are in the books or movies.