You see, I just knew as soon as I posted the pic of my wife's dislocated thumb that you'd all be grossed out, you couldn't stand to even look at it and then the solutions to our problem would stop flowing. 
I certainly appreciate all the assistance thus far, and if you have any further suggestions, we're all ears... I just have to get my ridding buddy back in the saddle some how???
Thanks!
Grizzly
PS - Her hand looks much, much better now. 
Grizzly,
There's an old and well-proven technology available now for HDs. It's been in use for mini-bikes, go-karts, and other equipment for 50+ years. Check out the Rekluse EXP automatic (centrifugal) clutch for HD:
http://rekluse.com/exp_hd.shtml. I also had a dislocated thumb, and nearly got one of these (still may have to if thumb degenerates with time). Saw it in action on a CVO RK at Sturgis in 2014; sure saves the clutch hand in stop-and-go traffic.
It's fully automatic, but can still be operated manually when you want. Here's the only down-side I know of with an automatic clutch: You no longer have the "parking brake" function of putting your bike in gear to park it on a hill, since the clutch is disengaged when the engine is not turning over. The company recommends a velcro strap around the front brake lever to hold the front brake engaged, which seems unreliable to me--but if you can live with that, this may be a solution. Good luck.