Faefever discussion

I had started a book and put it aside and I've been searching everywhere for it. I remember it had a dark cover, its a fantasy novel about a girl that gets a frantic call from her grandmother. She tells FMC to rip open the back cover and theres some ancient fae papers or a map to faerie. Her grandmother warns her of danger and that she needs to get to Ireland or maybe Scotland. That the same people who killed the grandmothers sister (possibly twin) have found her and they will be coming for the fmc too. Fmc had no idea her grandmother had a sister and all of this was confusing as she had a normal life.... thats as far as I got. It starts as a similar plot to the fae fever series by karen marie moning. If anyone remembers even vaguely similar books or plots please point me in that direction. I really want to finish this book lol