We had a few parents at our daughters elementary school who felt there was too much homework..
What the teachers at that school asked was for the students to do their homework and stop after 20 minutes (per subject) and go no further (3rd and 4th graders). This way the teachers could see where each student was at. Also homework was not required every night in every subject.. Math and language arts were, but Social studies science etc.. were a few times a week.
They also asked parents no to correct the homework.. Again the teachers wanted to see what the student was struggling with.. sometimes, this lets the teacher know if they did not cover the subject well enough or that particular question or problem needed to be explained to the entire class.
I know you said your daughter is working the entire time, but some parents had to be reminded that 20 minutes did not include the time to get a snack to go to the potty etc.. it meant the actual time working on the homework..
Yes, there were a few students that could not meet the time needed and complete all of it. , but they also were not missing any of the questions or problems that were on their papers.. This told the teachers these students knew the work, they were just slower.. This seemed to appease the parents.
For 2 of the parents, they did not like this, (they felt it sent a bad message to their children not to have to complete the work) they wanted all of the students to not have all of this homework. So they were given the option of moving their students to the class that allowed students to start their homework during class time..
Try to work with the school and see what you as a group can come up with. How many weeks have they been in school?
Is this a special private school that specializes in advanced curriculum or for advanced students? I know here in Austin there is a particular school that it is just known for being ubber advanced and the parents and students know it is aggressive with the homework.. I have heard some of those parents say they feel like that is all that they do at night is homework.