Great suggestions from AEH.
As to why school is all put together and home is not: It also sometimes happens that kids do well in school because they are so smart that they can make some attention mistakes and get away with it-- until the demands of school outstrip their executive function skills so that they can no longer coast.
I see that your child is 11. Over the next few years, teachers will be expecting more and more independence; kids who did well in the structure of elementary and early middle may flounder once that structure fades. You may find that your DD needs more training and support on executive function skills to keep up with peers in these years-- and you may want to watch how she's doing in classes to see if inattention starts to impair the quality of her work.
