When you say - 'cheating' are you talking about if it is 'submitted ' for a prize? or if a publisher wants it? or to your dd's self esteem?
If the child were younger, or going to a 'bricks and mortar' school or even homeschooling but doing the work without you 'keeping her company' I would say, sure, type while she talks it!
In your case, I would encourage you to transcribe from an audio file. And if that didn't work, then maybe sit and type while she talks.
If money is available, then I would sign her up for Online G3
Online G3 offers accelerated and engaging online humanities classes for gifted students. As parents of gifted children ourselves, the instructors and ...
www.onlineg3.com/I would also seriously bribe her to become a faster touch typist, at age 12 this is certainly possible, even with the LDs and bottlenecks. How many wpm does she have now? How many do you have? A little friendly competition might go a long way in this skill, which I think of as door opener.
Also - see if you can interest her in
http://ywp.nanowrimo.org/nowwhatThey have events all year long.
Also - look up
http://en.wikipedia.org/wiki/Christopher_Paolini for inspiration, listen to a few interview of him. Very interesting!
Also - this looks interesting:
http://owl.english.purdue.edu/owl/resource/677/01/in particular, you might get a lot out of their 'advice for tutors' such as:
http://owl.english.purdue.edu/owl/resource/687/02/My guess is that 'not getting it down fast enough' is part of her problem, but not all of it. Writting is a big task and requires teaching.
Love and More Love,
Grinity