Did they always have access to education? Did it coincide with first wave feminism? Has an elementary education always been available, but only recently access at a university level? Also curious about women of other races, but the initial question was when it was first available.
They've always had access to education so I'm not 100% what you're asking. The original compulsory laws from 1642 ("Old Deluder Satan Law") spoke to the count of children in a town, not the count of boys; meaning towns were expected to provide girls with degree of literacy necessary for their religious life.
Differences between the education of white boys and girls more comes down to the content, goal, and quality of education girls received. Most girls' access to education was focused on being a good wife and mother whereas for boys, it was about typically about independence and contribution to society. However, Quaker parents commonly educated children of both genders in the liberal, or classic, arts.
So if the question is when did white women get equitable access to education, it will depend on what type of university or college you're looking at and how you're defining access.