Try this with an empty gun, no ammo.
Have her turn her body about 45 degrees into her gun hand. The hand with the gun still stays pointed "down range" even though her body is turned. She should hold the gun so that the butt of the gun is level with her waist line, slide parallel to the floor. Then have her make a "C" with her support hand and clamp it down on the back of the slide. The support hand is going to stay in place. With the support hand gripping the slide (HARD), have her push forward with her gun hand sharply and strongly while holding the slide with her support hand in place. It's almost like a sharp jerking motion, the punch technique mentioned above. Using this technique she should be able to rack the slide after giving it a try.
Locking the slide to the rear can be a real challenge with a heavy recoil spring and small hands. I struggle with my shorter thumbs on some handguns. One way to get the slide locked to the rear is to insert an empty mag that will lock the slide back. Once its locked open, just take out the empty mag.
Hope that helps!