They stole my sister's soul.
When she turned eleven, they stole my baby sister away from us. One day, she was my smiling sister, always following when she was not wanted and eternally afraid of the dark. The next, suddenly the red-haired imp was gone, away and in another world: a changeling from Mother's fairy tales, a flesh and blood witch.
They stole my parents.
In the winter of 1978, they killed my parents. The demons inhabiting my sister's world murdered my parents and reduced their beloved home to a pile of rubble. At Christmas, Mother and Father laughed and smiled with us. Mother asked me if Vernon and I were ever planning on having children. By February, they were both dead. I insisted they be buried in the churchyard, but the mortician could never remove the looks of horror from their features.
They stole my sister's heart.
Shortly after our parents' death, my dearest Lily announced her engagement to man of her world. I had been trying to convince her to return to the safety of home, to avoid the fate of our parents. When I saw her face as she watched her fiancé, I knew it was all in vain. My sister was enamored of this bespectacled man who did not know about electricity or automobiles or the cinema or anything of our world. When I saw him take my sister's hand, I knew I would never see her again. Our parents' death caused bad blood between us and this was her knight in shining armor, saving her from her accursedly dull and dreadful family.
They stole my sister's life.
This letter proclaims as much. Not in so many words, but even they admit that she died. "A grand and selfless death" while "defending her son and family to the last" and she will be "remembered forever for her noble sacrifice," but my spirited sister is dead. My beautiful baby sister is dead. The infant I begged my mother to let me hold, the girl who took my dolls and stole into my room at night to talk, the young woman who would come home on holiday with stories of ghosts and magic and werewolves, the jaded woman from our parents' funerals: she is dead. She is gone. They have completed her wake and funeral in the way of her people. I was not told anything of it. I could not kneel beside her body, tearful and apologetic. I could not see her interred beside our parents, who shared her death. I will never leave flowers by her grave. She was taken by her world and her people; I have nothing of her left to me.
They gave me a baby.
For all of the things they stole from me, for all of my life that they managed to wreck and destroy, they gave me one thing. They gave me a little baby boy. Even now, he lays in his little basket, fast asleep. Once again, it is like Mother's fairy tales. The little witch-boy is left with his dreadfully dull relatives, waiting for the day that his people will find him and return him to his rightful place as prince of their world. Once again, I am stuck as the dreadful and cruel relative.
Even their gifts are curses, though. I know this. In their letter, they tell me as much. This baby boy, barely a year old, has my late sister's enemies. The demons who killed his parents and mine will still want to kill him. And when they kill him, they will kill me and my baby boy and my husband. In Lily's world, they have demons in man form, men who can kill with words and never be found again. In Lily's world, there are no defenses against this; if they can kill my sister and her love, they can certainly kill me and mine.
They will steal nothing more.
This boy, they will take him back when he is eleven. They want nothing to do with him until then, that much is clear. For the next ten years, he might as well not be the witch-boy the letter proclaims he is. He will be a child, just as my sister was a child. He will be easy to love, easy to embrace, easy to be family. And in ten years, he will be gone. He will return on holidays, knowing of his own world and his own powers, disinterested in my world and its problems. But even as a child, he will be a danger. His dreadful scar will mark us, to his people and to his enemies.
He, this boy, this witch-boy, Harry Potter, will not be allowed to take anymore from my family. His world has left me nothing but Vernon and Dudley. Vernon's sister is already suspicious of her strangely orphaned sister-in-law, asking awkward questions after my family and my sister. Dudley will not know the loss of a brother as I have known the loss of a sister. Vernon will not lose his son as my parents lost their daughter. I will not die by the words of witch-men and demons as my parents did.
I am sorry, little Harry Potter, but you will not steal from me.