In EY, everybody has school the whole day on Sunday and Friday is the half day. Unfortunately being that Sunday is a “day off” in America, having school that day interferes with family activities and other things that people arrange specifically to do on the day off.
As far as girls helping at home, my girls are in a school where they have school on Friday mornings until 11, until 3rd grade, and then they have off. That is when they should be at home helping their mothers.
Even in BY schools, the seminary age girls have off from right around Rosh Chodesh Nissan. In our school, seminary age girls are off from around 23rd of Adar. That usually gives enough time to help their mothers clean. Most mothers would prefer that their little girls be in school as they are still too little to help very much, especially not for several hours at a time.