My daughter is in 3rd grade and is 7 years old.
For her class... homework is everyday. It is a big jump in complexity, compared to 2nd grade.
For her, everyday homework consists of a Math worksheet or 2, some kind of reading comprehension or spelling worksheet, making sentences using 10 words from their list, and doing 20 minutes of reading for their daily reading log and AR reading comprehension test, they take.
It takes... about 1 hour to complete, if my daughter works on it without distraction... and I sit there, while she is doing it. To egg her on and cue her and answer any questions she has.
We do homework daily, RIGHT after she comes home from school. Otherwise, it gets procrastinated and she gets too tired.
Also right after we come home from school, I let her unwind... and have a snack. She is tired after school... and a kid needs to, unwind, afterschool. Then, after about 1 hour, she HAS to do homework. That is a daily routine.
On weekends, she also gets homework. And she has to do it, in the morning, before she can do anything else.
If she does not cooperate... then, I tell her she goes to school with incomplete homework and she WILL have to tell the Teacher why, herself. But, my daughter will do her homework. Because, going to school with it incomplete, is not a repercussion she wants.
The homework my daughter gets, is not always easy. Even I as an adult, have to look it over several times, to see exactly what the homework is.... and how to do it.
So I always, assist my daughter with homework. Not doing it for her of course, but as a moral support and clarifying things, for her.
I also find, that by the time they get home from school, a kid sometimes forgets, 'how' to do the homework... even if they may have did a practice of it at school in class together. So... there is that factor too.
If my daughter struggles with something, I tell the Teacher... and often find, that other kids are perhaps having trouble with certain math equations too.. so then the Teacher gives extra work on it, for practice and comprehension of it.
This is how it is for my daughter, in her class and grade.
Her Teacher said, 3rd Grade work, IS a jump in complexity. And in expectations, for the child. They are now in secondary level school, not "primary" grade levels. 3rd grade is a transition to that.
And in 4th grade, there is a big jump, in work complexity as well. So, in 3rd Grade, they are prepping for that etc.
Try to have a daily routine about homework... the same time, the same thing everyday.
If your daughter does not comply, then send her to school without it being completed.
Don't let her have privileges.....
HELP her with time management...because kids this age cannot time manage by themselves.
See if she CAN do the work, or if it is too much and too confusing for her.
ASK her 'why' she cannot do the work... or 'why' it is such a challenge for her.
Is she tired? Hungry? kids can't function and do homework if tired of hungry.
Is she a 'perfectionist?' If so, then maybe she does not want to do it because she thinks it will not be 'perfect' enough? Some kids are like that.
How is she in class? Does she complete her in-class work??? TALK to the Teacher about it.
all the best,