Chapter 1:The Boy and Girl who lived

This is the story of Harry and Y/n Potter. They are known as "the girl and boy who lived". After you know who killed Lily and James Potter the twins were sent to live with their aunt and uncle. BUT what if the twins have another aunt. Ashley Potter the twin sister of James Potter and wife of the dungeon bat. What will happen when the three meet? How will Snape deal with the twins? And of course which house will Y/n be in? Hufflepuff? Slytherin? Gryffindor?Ravenclaw?