Another book with a unique premise that goes off the rails with unrelenting violence and implausible situations. The girls the title refers to are victims of murder sprees where they are the only survivors. They are part of a therapy group to cope with the emotional aftermath. If the writer had stuck with that plot line that would be compelling enough to keep reading. The convoluted twists and conspiracies pepper the rest of this disappointing novel.  

CELEBRATING THE FINAL GIRL SUPPORT GROUP WITH GRADY HENDRIX – YouTube

Grady Hendrix – Wikipedia