Over the course of her later teenage years, ages 16 to 20, Mary Shelly's life was very action packed from running away with a poet named Percy Shelly, having two daughters, writing, and then eventually publishing Frankenstein.
Mary created Frankenstein during a time of tragedy
Both Mary and Percy Shelly visited Switzerland and were huddled inside a lot due to severe rain. With all this time indoors the Shelly's and friends Lord Bryon and John Polidori created a competition to see who could create the best ghost story. Out of this competition came Mary's Frankenstein.
Women are amazing!
Mary Shelly was in an emotionally distressed position from craving her mother's love and from the past being alienated from her father which gave her writers block. But after discussing Erasmus Darwins' experiments, she had a "waking dream" of Frankenstein which scared her enough to serve as an inspiration for the story.
Preceding the creation of Frankenstein, Mary gave birth to her daughter Clara who had died two weeks later. This could’ve served as an inspiration of Frankenstein as she said in a journal, “Dream that my little baby cam to life again.”
The book addresses several women's issues such as education, childbirth, and sexuality. Due to Mary's mother's death and the feminists beliefs that she left behind for Mary had affected Frankenstein.