The Story Sisters are Elv, Claire and Meg. They speak Arnelle, which only they understand (of course). They live with their mother, Annie, who is divorced and visit their grandmother in Paris.
The demons that cling to these girls as they grow into women are fierce, and the ghosts of the past that will haunt them forever are tragic and have desperate consequences. That makes this magic darker than usual, and the outcomes necessarily more sad than I would want for my heroines.
Nevertheless, the threads weaving this tale into a believable whole are the beautiful, evolving relationships - sisters, mothers, boyfriends and lovers. This is so well done, it's captivating.
I enjoyed the Story Sisters' story, dark and twisted though it was.
You may also enjoy The Rules of Magic by the same author, or what about The Accident Season by Moira Fowley-Doyle?