From things I have read over the years (and I admit it's been awhile), I think dyspraxia might be a vague and controversial diagnosis, but it depends on who you're talking to. My three older kids all have had speech delays (one is still in speech therapy and OT for fine motor and already did OT for sensory processing, etc.)
As far as treating sensory processing disorder, we had great luck with a short, intensive program in combination with the controversial listening therapy. (see e.g.
http://www.starcenter.us/ ) BUT, they were young children. I know they treat adults, but I think it's a lot more difficult to make changes in the brain.
My guess would be that she's a right-brained, visual-spatial learner. See
http://www.visualspatial.org/welcome.htm . There are lots of helpful articles at the articles tab regarding kids in school, though I don't know how much of that would be applicable to a young adult. If you think this situation applies to your daughter, there is a fantastic book that's out of print and hard to get but both of you might really appreciate reading it, "Upside Down Brilliance" by Linda Silverman (once in a while the used copies on amazon go down to a reasonable price but they're snapped up quickly).
probably doesn't help, but that's my two cents