A young girl's story of strength, resilience, and revenge

When Emily's entire family is murdered and she miraculously escapes, her life is permanently altered and her emotional health is scarred. On the run and taken in by a gang member, Emily makes it her life mission to train to seek vengeance for her family's death. For some reason, I don't tend to read series, especially when only the first is out. However, this sounds exciting and the premise could definitely create unique and engaging storylines.