Along with Dagny, Kay, and Cherryl, Gwen is one of the few good women (actually, one of the few women) that we meet in the book. As Hank Rearden's efficient and professional secretary, she's also the only other woman besides Dagny to be shown having a job and doing it well. Gwen represents the working girls of the country, women who aren't in positions of power or notoriety like Dagny but who are still trying to do a good job in spite of being surrounded by corrupt people. Gwen is quite loyal to Hank and she often gets emotional on his behalf. This is significant, since Gwen is otherwise a very cool and collected individual.
Tears were running down her face, against her resistance, beyond her control.
She saw him and said dryly, guiltily, in apology, "I'm sorry, Mr. Rearden," not attempting the futile pretense of hiding her face.
He approached her. "Thank you," he said gently. . . .As she looked at him, her mouth relaxed a little. The victim whom she could not protect was her only point of reassurance in a world dissolving around her. (188.8.131.52-111)
Notably, Gwen is one of the very few young people in this book who manages to resist the looters' ideology on their own. She isn't part of the strike in any way, but Hank tells her to make a run for it before he goes off to join the strike. So we have hope that Gwen escaped somewhere safe to wait for the strikers to return. Though her part in the book is rather small, Gwen provides us with a small picture of hope for the future.