Yeah, electric assist is something we've considered, though options are limited somewhat on a tadpole (which makes it expensive), and even used sparingly with regenerative braking current battery technology is distinctly marginal for decent distances. It's probably a better option than tandems, though: I'm a competent cyclist, but not a particularly strong one.
If Golden Motor made a hub that could take a 9-speed freewheel, it would start to look a lot more attractive. Batteries and controls are the easy bit. But as it is, I think the sanest option is BionX, and that's a complete system that doesn't really come in cheap.
Thing is, barakta was doing quite well last summer, when she was actually getting out and riding. Not fast, but within an order of magnitude of being able to do the average forum ride. The problem comes down to
spoons and motivation, and I'm not entirely sure that throwing electrons at it is a solution, as while it would certainly open up new route possibilities, it doesn't change the weather, the traffic, not having the time or the health to ride, etc, etc.