Just because a child doesn't pay attention or has trouble with homework doesn't mean they have ADD or ADHD. I've worked with so many children over the years, some with ADD and ADHD.
The ADD and ADHD ones are definitely different. A child who is spirited, energetic or simply not interested can be worked with. An ADD or ADHD child is one that nothing seems to work.
My daughter is spirited and spunky. If she's not interested, she's NOT INTERESTED and that goes for schoolwork. She has been evaluated and does not have ADD or ADHD. Oh, she can display the symptoms like there is no tomorrow but I can work with her. If she's not interested in her work, but she can't go to a party unless it's done, suddenly her skills come back! Suddenly the thing she couldn't do she can suddenly do. She also is a slow learner, so sometimes she just "gives up" and then she's goofing around instead of paying attention. If someone works with her and helps her, she not only understands what's going on, but is interested in the work and can pay attention perfectly.
I found with my daughter that her ADD SYMPTOMS (and she doesn not have ADD) appear as a coping mechanism. She doesn't understand what's going on. She goofs off. You solve the issue (work with her on understanding what's going on) and the symptoms disappear.
ADD children just can't pay attention even though they may want to.
Your daughter's teachers must have found a way to work with her. Maybe your daugher also matured a bit.
Why don't you talk to the teachers about the difficulty you have getting her to do her homework and maybe they can lend you some insight on how to help. Her problem may be academic, not ADD.