Dave knows whereof he speaks.
Also, I note that the forearm is too short, and so she has to over-extend her support arm in order to reach it. As well, her gun mount is too low- the butt is well down on her pectoral muscle and not in the 'pocket' of her shoulder where it should be. This is also preventing her from obtaining a proper cheek weld on the stock. A primary advantage of the long gun is that it gives you FOUR points of contact- shooting hand, shoulder, cheek, and support hand. That makes it much easier to use effectively.
My own wife is about 5'4" and i've been through the above issues re. gun fit with her as well. A properly fitted stock, a premium recoil pad, a long forearm, a good gun mount and good form will go a long way toward making shooting a shotgun painless, and make hitting with one much easier. Oh yes- and shoot light loads for training, too.
Mindset - Skillset - Toolset. In that order!
Attitude and skill will get you through times of no gear, better than gear will get you through times of no attitude and no skill.