Marinette's Little Sister

This story is about Marinette's little sister Marie who comes home from abroad. She is a famous model and dancer who has worked with Adrien before. She knows Marinette is Ladybug but what Marinette doesn't know is that a new hero is coming. One other thing is that Marie and Marinette have a crush on the same person. Will this knowledge destroy their relationship or will one be willing to suffer for the other.