Are you sure she wants to learn to shoot? Not everyone does (strange as it may seem to us), and there's no point trying to force something like that on someone.
If she does, "Go to a place in the country with a .22" is pretty good advice, IMO.
An even better idea, assuming she does want to learn, would be for her husband to take himself out of the picture as her teacher; that always sets things up for additional stress. It would be way better to have her learn from a professional in a women-only class -- ideally one with a woman instructor, but at least with someone who has experience teaching women to shoot.
It's actually not that uncommon for someone to be really stressed by the noise, especially if this was an indoor range. Even with hearing protection, it can be pretty overwhelming if you're not accustomed to it.
"Once the writer in every individual comes to life (and that time is not far off), we are in for an age of universal deafness and lack of understanding."
(Milan Kundera, Book of Laughter and Forgetting, 1980)