There's a great Kidspot article by dr job Coulson about why kids under 14 don't need homework, and there is a clip from an interview he did. Apparently he sent a letter home to his kids teachers every year at the start of the year about why his 3 kids wouldn't be doing homework and he only ever had one teacher disagree with him. Worth googling to check it out, and if you can't find it I can pm you the link.

You may find when you discuss it with her teacher and explain her reasoning, she is more understanding than you realise,

A lot of people think that homework is good for kids to at least learn time management etc, but it's not true. It an illusion that homework helps with that. The research shows that there are no benefits for homework until 14 and only moderate benefits for the rest of schooling. It's only adults who achieve outcomes from self study.

A pet hate of mine too. It's so frustrating, I've found that homework rarely provides kids with anything more than stress.