I believe you can do it, since most people can fabricate a system that works. It won't be cheap. I would suggest look around for body shops, reputable ones, and ask them.
I have been to a lot of shows and car competitions and they can pretty much do anything you want to the vehicle as long as there are enough funds. Yet for something worth while, and affordable, for her I believe just change the steering wheel to an aftermarket one. IE: Momo or any other brand of steering wheel with a built in air bag.