There is NO Mekor for the curriculum taught in these schools. However it’s very difficult to have the girls feel accomplished by just learning cooking and Hashkofa (especially in this world we live in that home ec is looked at as extremely petty). and it would also be “a Shanda” that the only accomplishment they feel is from their english classes. so we need to teach them unneccesary things that they can study, do homework on(another thing with no mekor) and memorize so that when they get their “A” they will feel good about themselves. And what about the girls that cant get “A”s because they are not cut out for this(which is totally normal because thats not what they were created for and have no obligation) they feel like failures when they can be the best wife and mom. another example of our chinuch system sacrificing the average students for the top ones.
one last thing,
Memorize the Chofetz Chaim’s introduction to the Hilchos Shabbos in Mishne Brurah vol 3? who thinks up this stuff??!!