I think the big thing is patience and reassurance that it's not their fault. Shoot we all crash sometimes.
I'm not sure if mine will ever get into it, she prefers drones anyways. No joke, the day after I got my Hobbyzone Champ she plowed it right into some bleachers and ripped the wing. I handed it over to her all while thinking this plane is super easy to fly, I bet my wife could do it too (and she seemed excited and wanted to). She really hasn't flown since although I've gotten her to fly a little on the sim. But like I said, she has told me she prefers camera/altitude hold drones more than planes. She's not a super hardcore RCer.
My old man told me this words a long time ago: leave your wife alone when you need a hunting or fishing buddy. I guess he could also add flying buddy to the list.
He is a wise man.
If your wife shows interest in the hobby your are a very lucky man and I´m so glad for you. I do not see much girls into RC around, actually never seen one.