Barnard is a private all girls school.
To be honest, I wasn’t even sure Barnard still existed after Columbia was opened up to women. My female-only college floundered after all the women’s colleges went co-ed in the 70s. But the original poster is essentially correct: any Columbia guy would have gladly sold or given her some.
For all practical purposes, Barnard is Columbia. You can be assured she had male college students in her social circles.