10-15 mins a week does seem light to me. I'm pretty sure I was doing the same up through 6th grade, though, mostly because I had plenty of time to do the homework in class. If that's what's happening in your DD's case, it's probably an indicator that she's not being challenged adequately.
I'd be careful about advocating this, though, because the result is likely to be seeing your daughter loaded down with busy work. Given the choice between no homework and homework for homework's sake, I'd gladly take the former... as would, no doubt, your DD.
