The Potter Twin - Marauders Era
Sapphire RiverMist Potter was never normal. She argued with her family constantly, and started showing signs of magic at two months old, talked way too early, and was born 3 months early, literally dragging her twin into the world. When Saph gets fed up with her family, if you could call them that, she gets disowned. When her letter arrives 1 year late, she goes to Hogwarts and meets someone she never wanted to see again...
All the characters in this book belong to The Queen J.K. Rowling, except for Saph and other random characters that I have made myself.
Also, I got the plot from a lot of different books on Wattpad, so if you read something that sounds a lot like a different book, than it probably is.