If she is speeding through things, that may be more along the lines of combined-type ADHD or hyperactive-impulsive, than inattentive. With both of my kids (one combined type and one is maybe inattentive type--I'm not sure yet if he really has ADHD), the main issue seems to be focus, which includes schoolwork. So they come across as doing things slowly and have work piling up. If a child is getting the work done and is fast, then I would guess ADHD is not an issue unless it's the hyperactive-impulsive type. But I'm not an expert, this is just based on my own observations. I'm not clear from your posts whether she is able to focus on schoolwork, and if she can is it just for a limited amount of time and then she starts to zone out or get distracted, at least with things that don't interest her much? If she really loves writing, she may be able to focus on it well, just like my DD is able to focus on reading for long periods of time (but when I read to her, she does tend to wiggle or actually get up and pace around--she'll look like she's not paying attention even if she is).
