The primary theme explored throughout In Her Own League is institutional sexism—in other words, the systematic gender-based discrimination within an organization—especially for female leaders in male-dominated fields. Throughout the novel, Reese constantly has her authority questioned, undermined, and challenged. Much of this is because of the systemic biases against women built into the world of professional sports.

In her very first chapter, Reese is well-aware of this institutional bias when she notes “there’s been a long-standing and very outdated position of ‘no women in baseball’” and that “there are far more people out there [than the four sexist men on her advisory board] hoping for [her] failure” (25). Instead of the press conferences focusing on the franchise or the team, many reporters’ questions or comments are directed toward Reese or focused on her gender, such as asking if she feels she’s in over her head with the role, or what she’d say to everyone who believes she isn’t the “right man for the job” (45). 

Reese is also questioned about how she would balance her home life with her career if she were to marry and have children in the future. The novel makes it clear the other owners (all male) don’t have conferences focused more on their gender than on the franchise or teams themselves, nor do they ever get asked about how they balance their career with their families.