As many know, Sarah Schenirer started a movement that influenced learning for women, and the Bais Yaakov system we all know of today.
Even though learning Torah Shel Ba'al Peh was heavily discouraged until recently (see here for a wonderful introduction on the topic), doesn't the Rama write in Shulchan Aruch Y.D. 246:6:
ומ״מ חייבת האשה ללמוד דיניס השייכים לאשה
Which would seem to imply that women were very much instructed to learn Halachot and Mitzvot relevant to them (all halachot and mitzvot that women are bound to abide in).
If so, why was Sarah Schenirer's contribution such a monumental shift? Were women learning relevant Halacha (presumably in schools) prior to the movement? If not, where did they learn Halachot and Mitzvot that they needed to know?