The stark girls

When too little girls from Canada move to nyc at the age of 9 and adopted by a billionaire and his wife what happens when two year later one of the girls gets a note from a Specific magic school when a little scar headed boy goes and the Other gets Taught by a Certain red witch 

The girls names are Michelle and Rhiannon  and All rights go to the. Original creators I known nothing and is just using the names and don't be mad if you don't like it also this is set in like 2015 and the hp characters have phones