I have been given the following essay topic: "In Frankenstein, the female characters are shaped as much by social expectations as by their own...

In Frankenstein, most of the female characters act according to social expectations of what women should do. This could be part of a larger feminist critique made by Shelley in the novel. You might notice that most of the female characters and all of the mothers are killed at some point in the novel, by illness or by violence. Mothers are strikingly absent in the novel, as this helps Shelley critique Victor's presumption in creating life on his own out of pieces of dead bodies, as he plays God and leaves the female body out of the equation. Note Victor's hesitation to build the female creature because he fears she and his original creature will "naturally" reproduce; this leads him to destroy the female creature before it is completely finished.

In the novel, Victor's mother, Elizabeth Lavenza, Justine, and Safie are the major female characters, and they exist mostly on the periphery of the story. Victor's mother dies early on, beginning the absent mother motif (later in the novel, the DeLacey family is without a mother, as well). Victor's mother, Caroline,  seems to be a fairly typical mother of the early 1800s; there isn't much evidence as to whether she "chooses" one action over another, but certainly becoming a wife and mother would have been expected of her by society. She seems to be warm and loving, and Victor has fond memories of her.

Elizabeth is like Victor's mother in some ways: she is meek and cheerful and maternal. She helps to nurse Mrs. Frankenstein in her illness and then basically takes her place in the family as caretaker once Caroline has died. Elizabeth later becomes a victim of the creature's violence due to Victor's destruction of the female creature he had promised his original creature. While she does choose to act as a mother figure to the Frankenstein family and she does choose to marry Victor, these actions are also in line with the expectations of her era.

Justine Moritz is probably the best example of a character who does not control her own fate. Justine is wrongly framed for the murder of Victor's younger brother William. The creature actually killed the child and planted evidence on Justine, who had been a loyal and beloved servant in the Frankenstein home. Clearly, her murder conviction (though unjust) is an example of how the character does not fit social norms for 19th century women, but she definitely does not have a choice here. The character who could have helped her was Victor, who knows the creature killed William, but he does not, and Justine is executed. Even if Victor had saved her, this act would be an example of the stronger male character rescuing the helpless female, which would align with social expectations for men and women.

Safie is the female character who perhaps makes the most decisive action when she chooses to leave Turkey to be with Felix DeLacey. She had previously been a slave and so was oppressed, like many women of the time, though more obviously so. Eventually she falls in love with Felix as he tries to help her father, and when her father later betrays the help given, she chooses to leave him to be with Felix. This is a choice, but it is a choice between two men who will provide protection for her, so it's still somewhat traditional as far as gender norms go.

Most of the evidence in the novel suggests that female characters are less shaped by their own choices than by social expectations for women.