HP the Neglected Child

(The heroine: Petunia, the hero: Regulus Black, please bear with me if I write this for the first time. I will update it from time to time. The content is more daily. The heroine is a real child and doesn't know the plot. She has the bad temper of a child, so don't enter if you don't like it.) After Penny was born, she was always the neglected child, going to the small town church where her best friend, Sister Anne, was when her parents weren't looking. The younger sister was discovered to have magic, met new friends, went to a magic school, and the two sisters drifted apart. The encounter with Regulus was an accident. Due to the blessing of God, she was a Muggle girl who could fight with multiple adult wizards when she was young, but did not think highly of wizards. She was a pure-blood wizard who was prejudiced against Muggles due to the influence of her family's education since childhood. The Death Eaters' pursuit made the two of them meet unexpectedly, and by chance, the bond between them gradually deepened. God and pagans, the family philosophy of pure blood supremacy, what will be the outcome of the magical version of Pride and Prejudice? Ps: The heroine is actually capable of magic, but her magic does not exist in her bloodline, so the Hogwarts Book of Admission cannot detect her. Her magic comes from God's blessing and cannot be inherited.