Final answer:
Mary Shelley indeed made several contributions to gothic literature, most notably through her novel 'Frankenstein' and short story 'The Mortal Immortal,' both of which exemplify key elements of the genre.
Step-by-step explanation:
Mary Shelley made significant contributions to gothic literature, which is a true statement. She is well-known for her novel Frankenstein, which has become a classic in the genre and exemplifies many of the gothic elements such as the supernatural and the exploration of human psychology in extreme conditions. Shelley also wrote "The Mortal Immortal", a short story that delves into themes of immortality and the supernatural, which further solidifies her place in the realm of gothic literature. Her works contributed to the evolution of the genre and continue to be studied and admired for their innovative and haunting qualities.