Regulus Black x Reader

Y/n Potter was up until recently going to Beauxbatons. However she was expelled due to dueling and threatening to kill another student, Dumbledore decided to give her another chance. She is sorted into Slytherin but James still takes her in and she is known as "The Mini Marauder". This story will be told in first person (Y/n's Pov) and possibly at parts another character. She meets Regulus as Sirius' cowardly baby brother who was (supposedly) loyal to Voldemort. She forms a friendship after Regulus is assigned to show you everything there is to know about the castle.