GTD for the home is no different from GTD anywhere else; it sounds like the real problem for her is having any room at all in that schedule for implementation!

First, as for the book, would she have an easier time using the audiobook, either around the house or on her way back and forth to work? It doesn't have the detail that the book does, but if it's the only way she can get the information, go with it. Since you know the system as well, be available to fill in anything the audio version misses.

Even if she can't do that, can you set up a weekend afternoon to coach her through getting her system set up? Going through the process herself may be enough to get her started, even without any version of the book. Get a sitter, or at the outside, wrangle the kids yourself in another part of the house so she can focus on her processing. In a sense, her position is very like the busy execs the David describes consulting with, for whom carving out a block of time to set up a system is the biggest challenge.

Make sure that she's got work space of her own -- an in-tray and a whiteboard won't do it! If she's trying to study as well as all the rest, she should already; if she doesn't (and I say that having no idea how much space you have or what your living arrangements are, of course), you can help her by helping her get something arranged.

And one more thought -- there was a good thread before the holidays over on the google group about someone who wanted to get his girlfriend started on GTD with a sort of an organizational gift basket; there were a lot of good ideas about the kind of supplies you might give someone to get them started. Maybe, given her tight schedule, get her the book, folders, labeler, etc in advance so she's ready to go; and print up "gift certificates" for protected time, babysitting, help with heavy lifting, or whatever else might apply?