+1 To Cuda and Tackle.
I like to claim I'm 5'7", so I've been fighting the short problem for over 30 years of hunting and shooting since I was a kid. Length of pull is a big problem for a short shooter, Tacklebury touched on the other issue: weight. Weight is an issue, but leverage is the problem. A short person's arms just aren't long enough to get the leverage to hold the gun properly. Tacklebury has a good set up pictured, if you go with the laminated have a gunsmith fit her and install a good recoil pad. The slip on pads increase LOP too much for a short shooter on the range.
Here is my set up, it is an ATI adjustable stock. I have a 357 reamed to Max and a 44 mag barrel on this frame. In the FAQ's the stock has bad reviews and I don't disagree with them. But, if you take the loop side of a heavy duty Velcro strip and place on the rail the stock slips over it is so solid the stock takes a lot of effort to adjust. The whole rig weights less than 9 pounds with 6 +1 rounds.
Also, google "rifle recoil table" and "shotgun recoil table". That will take you to Chuck Hawk's site. You will see a 44 mag is not much different than a 20 gauge in terms of recoil. The 357 mag is acceptable for deer, as long as you keep it inside it's limited range. Reaming to Max basically gives you a 30/30, but you have to hand load. The other thing with the 357 is she can shoot 38's, and the 38's are just fun. There like a big 50 yard 22 lr.
As for the turkey gun, I cannot imagine going below a 20 for turkey. Work her up slowly with the lightest loads you can find (with the good recoil pad), and if that doesn't work I would look for a semi-auto. The semi-auto doesn't actually reduce recoil, but they do smooth it out. The single shot is a sudden shove, while the semi-auto is more of a push.
Good luck!