For the writing issue, I highly recommend keyboarding. My fourth grade dd has an issue with handwriting as well, and she recently learned to type, and I've already noticed a difference in her creative writing (that she does at home just for fun, silly stories).
She is allowed to type in her montessori classroom - they have little devices called Alphasmarts or something - and they also have access to the computer room at some times. So I'm hopeful that soon she'll be typing most of her more lengthy written output.
In contrast to your dd, my dd has slow-er processing speed. She also has slow motor output. Her overall processing speed was average, but her coding subtest on the WISC was around the 25th percentile. The coding subtest requires more motor output. When we had her tested, the psych recommended keyboarding.
There are a number of free on-line programs for learning typing. My dd liked this one:
http://www.bbc.co.uk/schools/typing/levels/level1.shtmlI don't know about the math issue - sounds like something a visual-spatial learner might have trouble with. Somewhere along the way, perhaps even on these boards, I saw one piece of advice that might help. When she has to explain, maybe she could think to herself what she might say if she was trying to teach the problem to another child.
