What is she shooting?
I would try switching her to a VERY low recoil gun for awhile, such as a .22 where there is almost no recoil and see how she handles that. After two hundred or so rounds she may find this isn't so bad at all.
You may also want to just do dry fires with her over and over again with snap caps try it for about fifteen minutes to a half hour every night. She'll know it's not loaded and so she most likely won't flinch. After she gets comfortable (if not bored) with pulling the trigger and NOT flinching then easing her back into live fire.
Another thing would be to tell her to concentrate on her front sight and where it's pointed rather than on what happens when she pulls the trigger.
Those are my ideas.