.... apparently, which makes us incredibly unreasonable for insisting that she does an hour a night (she's in year 8).
I'm tearing my hair out about it. She's had detentions, she's been grounded, we've had terrible arguments. She will not do it, except in extremis when she's being threatened by her teachers with dire warnings, in which case she does the bare, bare minimum. The quality of her work when she does do it is very poor. 
DH and I are at the end of our tether with it. She also often fails to stay on task in class, talks a lot, doesn't complete work, is rude to her teachers (challenges them in class if they take issue with her behaviour).
She thinks this is 'normal' behaviour for a child of her age. We think not.
I'm sure there are children out there who make an effort and don't need constant nagging and threats to do homework.