Age is always relative. Mary Shelley was some two months shy of her twentieth birthday
when she began writing Frankenstein and well past twenty-one when the novel appeared
in print. Moreover, before she began the novel toward the end of June 1816, she had
registered experiences highly unusual for a young woman in the constrained environment
of Britain, including eloping with a married man and twice giving birth. That said,
it is true that the author was in years yet an adolescent when she wrote this novel
and that, historically speaking, most of its readers have been struck by a range of
knowledge, maturity of conception, and intellectual ambition unusual in one so young.