Joseph,
There always were girls who learned
The Innovation if there was, was as an official institution
As someone who was involved in a superior bais yaakov High School in North America for
some years previously ,one even presently can honestly weigh and debate whether girls being educated in institutions Is better than other options at least in theory
One fact that’s rarely considered in the Perennial discussions was that females had just gotten suffrage .
There therefore desperate need for them to be educated
iirc Frankfurt Had girls education institutionalized since 1853