Perhaps there's a way for her to use what you've got...
Instead of her holding the pistol out toward the front and trying to pull the slide to the rear with the other, non-shooting hand, have her turn (assuming she's right-handed), 90 degrees to the right, making sure she keeps the muzzle pointed downrange while she turns. Then have her grasp the TOP of the slide with the non-shooting hand and, holding the sidearm close to the chest, push both hands towards each other, racking the slide that way...the same arm action as if she were pushing her palms together. Finger off the trigger the whole time, right?!
See if that helps. It helps my Lovely Bride. Good luck.