Marilyn is a twenty-year-old college student yearning for independence in 1960. Passionate about writing, she chafes against societal expectations dictating she focus solely on marriage. After causing a public scandal, her parents send her away for the summer. Under her great-aunt's strict supervision, she begins to discover alternative paths for her future.

Ada is Marilyn's seventy-five-year-old great-aunt. She operates a highly successful matchmaking business within the Jewish community. Despite her profession setting up young couples, she remains fiercely independent and unmarried. She is strict but perceptive, aiming to teach Marilyn about the realities of adulthood.

Daniel is the local rabbi's son whose stolen kiss with Marilyn sets off a neighborhood scandal. While his parents expect him to become a rabbi, he secretly harbors dreams of working as a photojournalist. He possesses a calm demeanor and treats Marilyn's ambitions with genuine respect.

Lillian is Ada's longtime live-in companion. She spends the early part of the summer away from Philadelphia caring for her dying mother. As a former World War I nurse, she brings practical warmth to Ada's household.

Walter is Marilyn's traditional father. He views college primarily as a waiting room for his daughter to find a suitable husband. He prioritizes social reputation and family duty above personal desires.

Rose is Marilyn's mother. She adheres to traditional expectations as a housewife but secretly supports her daughter's literary interests. Having spent a summer with Ada in her own youth, she hopes the time away will help Marilyn avoid further scandal.

Freddy is a handsome lifeguard who quickly catches Marilyn's eye at the park. He actively pursues her despite Ada's active attempts to match him with other local women. His outward charm masks rather conventional expectations for a future wife.

Shirley is a young woman from a newly wealthy family who befriends Marilyn on the streets of Philadelphia. Her family summers at the Jersey Shore, where she socializes heavily. Ada privately views the Goldmans as vulgar social climbers.

Thomas is a young Black medical student. He performs odd jobs and handles heavy lifting for Ada's household. He shares a respectful relationship with the matchmaker, who treats him with notable generosity.

Frannie is Ada's maid. She works for the matchmaker in both Philadelphia and the summer home in Avalon. She receives generous time off and housing for her family during the summer months.