You need to have a sit-down with the teacher and ask her to explain what techniques she has been using, how she evaluates how your daughter is progressing, and what she identifies as her needs. Your daughter's standardized test scores may not reflect her actual writing ability, but may be a function of her ability or inability to attend to the test or take a test.
Some kids bomb on tests but can produce pretty good writing given structure and enough time to edit. Kids with ADD frequently have difficulty not with learning the rules of writing and grammar but in organizing their thoughts and applying the rules of writing and grammar as they write. They tend to be impulsive and scattered in their thinking, so when they write, they need to have structure before they start. One good tool you could suggest to the teacher is a computer program called Inspiration, which helps kids create graphic organizers and outlines, which in turn helps them organize their thoughts.
I teach writing (among other subjects in a school for LD kids) to 8th graders, and we have double periods of English a day three days a week and a spelling class on the days we only have one English class. With this kind of intensive intervention we see one-to-two years' growth on average each year, and occasionally we see exceptional growth. Writing is a very complex skill, and your daughter may need tutoring to progress more. Try to enlist the teacher as your ally in identifying and addressing your daughter's needs, not your enemy.
I might suggest for spelling that she try Looking Glass Spelling. You can see a sample on my website at www.gwhizresources.com. I use it with my 8th graders. I'd suggest levle 2 for a 5th grade reading/spelling level.
Good luck.
Fern
G. Whiz Educational Resources, Author of Looking Glass Spelling and G. Whiz...I Finished My Homework!