Lara is the protagonist of Tom Lake. She is 57 years old in the present narrative, and the nested narrative covers a period beginning when she first got the role of Emily in Our Town in high school, through the summer at Tom Lake, where she turned 25.

Lara has complex relationships with her daughters, especially Emily, who is named after the role that Lara associates with an exciting and significant coming-of-age motif from her youth. Their conflicts and eventual reconciliation and mutual understanding develop the theme of How Daughters Reflect and Refract Mothers. As Lara opens up throughout the novel, she tells her daughters more about her life than they ever knew. She realizes that although they had the bare sketch of her history, they had filled in the gaps with supposition. Through the process of telling her history, she gains new intimacy with her daughters

Lara is honest about her feelings, even if they may seem inappropriate. While Lara maintains an awareness of her own motivations, she often reacts impulsively in ways that can come across as thoughtless. For example, when she and Nell talk about their pandemic isolation, Lara asks her clearly miserable daughter, “Don’t you sort of love it, though?”—an insensitive question that prompts Lara to realize afterward, “I am projecting, of course.