Complex sentence: Molly Hartley (Haley Bennett), a 17-year-old girl, was stabbed by her mother and survived but, although she has healed from the wound itself, she is still haunted psychologically by the experience.
Split into simpler sentences: Molly Hartley (Haley Bennett), a 17-year-old girl, is stabbed by her mother and survives. Although she heals from the wound itself, she is still haunted psychologically by the experience.