Silent, but still there

During the Halloween night when Voldemort went to the Potter home, it wasn't Hadrian that was declared as the Boy Who Lived, rather his twin sister, Hannah.
Hadrian grew up neglected while Hannah got everything.
How will this change when Hadrian begins at Hogwarts?

- I own nothing except plot and Hannah. All credit for characters goes to J. K. Rowling, but I have changed a lot of their core.