Kolar Arms...http://www.kolararms.com/
Best customer service of all we have used. And we have used a lot of them. Jeff Mainland makes you feel like the most important customer they have. They will custom fit the gun to you. You can get them used from Indiana Gun Club too. They stock new and used. I just sold my Perazzi combo and switched to Kolar combo, instant improvement in my Trap Scores.
I got a Teeter inverter through Costco and hanging upside down for 15 minutes really helps the back pain. My issue is Thoracic spine, 3 surgeons have now told me "bad problem, but no fix". So muscle relaxers and hanging are all I can do for it. Dogs love it because I am an easy target for the face lick. Yuck!
See if you can get her to spend some time with a private instructor. A little bit of good advice is better then all the well meaning help you get from others at the range. See if any of the other women shooters also mentor or teach.
Minor power factor and allowing the lower end of the gun to move back when the slide is. it never can reach full cycle. Tell her to think about pushing her shoulder forward two inches and push into the gun. It works every time.