Purplesquirrel: YES, I have ADD, and I was that scatterbrained kid who couldn't remember everything or complete anything. I had a wise teacher in 7th grade who arranged with my dad that if I did not finish my homework, I had to stay after school or miss free period and do it in her classroom. My grade went from a 60something to a90something in a matter of weeks. At first I resented it, but I felt much better when I looked at my report card.
As far as remembering to bring things, though, at age 41 I still struggle with that. In grammar school I was simply incapable of doing it, and needed help and a break. I don't think you using a checklist in the morning to remind her of things she needs to have with her is enabling.
My daughter has many of the same problems. She told me today that her new teacher checks everyone's planner before they leave, and I silently looked up to the sky and said, "THANKS!"
When I didn't tell my dad about my assignments or what I forgot, it was mostly out of shame, not stubbornness. But I had to be an adult to be able to have that level of understanding about myself. Good luck to you and your daughter both.