Despite the fact that Frankenstein was written by a woman (Mary Shelley), women's voices are largely absent in the text. The story is a frame narrative told by Robert Walton, Victor Frankenstein, and Frankenstein's monster. While women are present in the story—such as Elizabeth, Justine, Safie, and the monster's unfinished mate—they are generally relegated to being minor characters, plot devices, or servants to men. Looking at the four aforementioned characters shows how this is the case.
Elizabeth, for instance, is to be Victor's wife. In Shelley's first description of Elizabeth, she is described as "docile and good tempered ... no one could better enjoy liberty, yet no one could submit with more grace." Her submissive qualities are highlighted, and the rest of the paragraph used to describe her continues to talk about her affectionate and subservient nature. Further, she is ultimately murdered at the hands of a man (the monster).
Similarly, Justine plays the role of servant to the Frankenstein family. Justine is described as a provider of happiness to Victor: "if you were in an ill humour, one glance from Justine could dissipate it." She is also killed. In this way, both Justine and Elizabeth are submissive and relatively two-dimensional characters who exist generally to make men happy and serve as plot devices to be murdered at the hands of the monster.
Safie, Felix's betrothed, is a Turkish woman. Her presence exists as a convenient plot device to teach the monster English. However, especially during the early 1800s, when the novel was written, she also represents an exotic, "Oriental" object (see Edward Said's book Orientalism). This exotic element must be removed, and thus she is acculturated by learning English.
Finally, the monster's wife is never given life by Frankenstein. In fact, her body is destroyed at his hands. While the male monster is allowed to receive life by the god-figure of Victor, the female counterpart is not afforded this right, and again, this destruction of the woman figure acts as a plot device to spur the monster into a murderous rage.