"Yours, Constance" by Emily Hayse

Set in the Roaring Twenties and tinged with magic, Your, Constance is an atmospheric treat.  Constance Hanover seeks solace at dazzling, deafening parties for the pain of having lost her sister in a tragic accident.  There, she meets Ella Whittington, sixteen-year-old heiress with her own sad past to haunt her.  Ella befriends Constance despite the latter's tendency to try to mentor, mother, reprimand, counsel, and boss her... all in nice ways, but I did wonder once in a while if Ella wasn't goi...