Sophie's Sister (Mamma Mia x Harry Potter Marauders Era fanfic)

What if Donna Sheridan had not only one daughter but, two daughters. Isabella and Sophia Sheridan, also known as Izzy and Sophie. (Isabella x James) (Sophie x Sky) (Donna x Sam) (Tanya x Pepper) (Rosie x Bill) (Harry x Petros) (Lily x Remus) (Ali x Sirius) (Lisa x Peter)