Where can I find information on Women's college attendance pre-1940 on the interweb?

Does this help?

From the above linked source:

Educational Attainment
The increasing rates of school attendance have been reflected in rising proportions of adults complet-
ing high school and college. Progressively fewer adults have limited their education to completion of the eighth grade which was typical in the early part of the century. In 1940, more than half of the U.S. population had completed no more than an eighth- grade education. Only 6 percent of males and 4 per- cent of females had completed 4 years of college (table 4). The median years of school attained by the adult population, 25 years old and over, had reg- istered only a scant rise from 8.1 to 8.6 years over a 30-year period from 1910 to 1940 (table 5).
During the 1940s and 1950s, the more highly edu- cated younger cohorts began to make their mark on the average for the entire adult population. More than half of the young adults of the 1940s and 1950s completed high school, and the median educational attainment of 25— to 29-year-olds rose to 12.3 years. By 1960, 42 percent of males, 25 years old and over, still had completed no more than the eighth grade, but 40 percent had completed high school and 10 percent had completed 4 years of college. The cor- responding proportion for women completing high school was about the same, but the proportion com- pleting college was somewhat lower (table 4).

@bkcunningham Thank you, I have looked through a big chunk of it, and it only gives females after 1940 from what I am seeing. Am I reading it wrong?

Sorry just got to the slide on page 21. White females prior to 1940 were more educated than any other group.

Did you see the chart on page 21?

Also, page 69: Percentage of higher education degrees conferred to females, by level: 1869–70 to 1989–90

Table 23 sums it up.