Chapter One - To love and to sacrifice and to promises unbroken

She has her mother's eyes. Unbeknown to most of the wizarding world, including herself and Harry, Primrose is Harry Potter's twin sister who was entrusted to a certain Hogwart's professor when she was just five months old.
Severus made a promise to raise her better than he'd raise his own child but will he be able to tell her the truth before she finds the truth out herself?
Please note that all of the pictures (cover and the ones included in the chapters) were taken from google images; I DO NOT own them.
I also do not own Harry Potter, I only own this plot.