Parents can teach their children to write! Using the best writing curriculum (in my opinion the Institute for Excellence in Writing) they can teach an 8 year old or an 18 year old (the only difference is the speed it's taught). But the learning curve when using IEW can be steep.
I recommend you be trained in the program before you teach. In my experience, although the writing pattern is clear, to teach it successfully you need to see it done. I enjoyed Andrew Pudewa's training dvds, but they cost $169 (although I heard Diane Hopkins at Love To Learn might be willing to rent her set out). So, I teach a class for $20 and in 4 hours take parents through the text explaining and demonstrating how to teach using the IEW method.
The next Parent Writers-Training Class is:
Date: Saturday August 17 2013
Location: Chris Jones Conference Room, 680 E. State St. Lehi, UT
Bring: A copy of All Things Fun And Fascinating (you can buy at www.ldfr.com, use the code "Valerie" for free shipping). And bring a lunch!