Having the wife or gf crash does suck, especially if you're the one that talked them into getting a bike. That is one of my biggest fears too...
Remember if the helmet hit the ground, even if it didn't crack, it's safer to just buy a new one. When she is able to get back on a bike again, make sure she has healed and rebuilds her strength before doing a long ride or anything too strenuous, otherwise the likelihood of another crash increases due to fatigue and muscle imbalances. Good luck and hoping she has a speedy recovery!