If ever there was a woman in literary history that deserved a biopic, it is Mary Shelley. The daughter of political writer William Godwin and feminist writer Mary Wollstonecraft had a rocky childhood, and went on to marry young, as was the custom of the time. She published “Frankenstein, or a Modern Prometheus” at just 21 years of age.

The new film, “Mary Shelley,” seeks to present a snapshot of the life of Mary Wollstonecraft Godwin, and the chain of events the led her to create one of the most enduring horror tales in all of literature.

Elle Fanning stars in the title role. The story begins in a cemetery. Sixteen-year-old Mary finds solace in this place. It is an escape from the unhappy home where she always seems to find her step-mother’s bad side. The opening begins like so many of these films do. With Mary, all alone in some peaceful place. And then realizing it’s time to get home, and rushing on her way. Once through the door, she encounters her step-mother, Mary Jane (Joanne Froggatt), and they argue, as usual. The film hits all of the cliched bits required of a biopic set in the Regency era. Shelley’s family is reduced to one step-sister. An older sister and a younger brother are erased from history in this story.

The production design starts off right. The dusty, muddy streets of pre-industrialized London come to life. Mary’s father’s bookshelves sag under the weight of heavy tomes. The lighting is dark. It all adds to this dark and confining world the Godwins inhabit. It’s interesting to ponder that an enlightened political mind such as William Godwin (Stephen Dillane) lived in the literal dark. And Dillane’s introduction as Mary’s father is appropriate, if largely unoriginal.

Because of problems at home, Godwin sends his daughter away to friends in Scotland. There she forms such a close attachment with Isabel Baxter (Maisie Williams) that the banishment feels more like opportunity. There are several problems with the Scotland scenes, and these problems only grow as the film continues. Time becomes illogical, with no way to follow its passage.

And, we meet the poet Percy Shelley (Douglas Booth). Booth is a garden variety British white boy with trademark messy hair and smirk. If he was on the list of not-quite-rugged-enough actors considered for the part of young Han Solo, it would be unsurprising. His performance as Percy is flat and uninteresting. Mary’s sudden and complete infatuation only makes sense in the context that he is probably the first boy to notice her.

After many months that turn out to be only a couple of weeks, Mary is called home to the bedside of her ailing step-sister, Claire (Bel Powley). Powley is the bright spot in this movie. Her wide-eyed wonder and desperate need for love carry her through the years of heartache the two girls will endure. She is funny and sweet, and avoids going too much over the top with her performance.

The same cannot be said for Tom Sturridge as Lord Byron. From first introduction, Byron is a smarmy, off-putting man who inexplicably catches Claire’s eye. Sturridge doesn’t give him any of the charm the real Lord Byron was said to possess. Certainly the poet was known as a bad boy of the age, but he knew how to wield that reputation. Sturridge seems almost intent on giving us a version that no woman in her right mind could ever look to for hopes of romance. And yet, Claire falls in love with him anyway.

Besides boiled down characterizations, “Mary Shelley” suffers from major issues with the passage of time. It is almost impossible to follow the timeline of the story, or to figure out where we are in their lives. Scenes that seem to take place over an evening turn out to be months apart. People disappear without a word and when they reemerge we don’t know if it’s the next day or the next year until we are told.

And that’s the biggest complaint with the film. Too much of the pertinent information—at least what is not jettisoned for narrative purposes—is conveyed through telling it, rather than showing. We are told about Mary’s relationship with her step-mother far more than we see it. The same for her relationships with her father, with Percy, and with society, for that matter. We do see some of Byron’s bad behavior, but far more of it is told than displayed. And we are constantly reminded that Mary and Percy love each other. Because they say so, not because they ever really show it.

It’s unfortunate that such a fascinating life should be confined to a film of such limited scope. Director Haifaa Al-Mansour delighted audiences with her award winning debut, “Wadjda.” Unfortunately, she doesn’t carry that same promise with her to this work. The film isn’t a disaster, but it fell far short of its potential.

GRADE: (★★)

“Mary Shelley” is distributed by IFC Films and is in theaters today.