Originally Posted by NSR500
If you insist on the shotgun, get the Mesa Tactical M4 recoil reducing stock set. It'll allow a better LOP for her while the pneumatic shock absorber cuts felt recoil. It's no substitute for better training, but can give her the confidence she needs to train better.
I wouldn't choose my shotgun for home defense, but I have a Mesa Tactical Urbino Stock on my Remington 870. Made a huge difference in my shotgun handling skills, because it reduced the LOP to twelve and a half inches. The limb saver butt pad that comes on it was enough recoil reduction for me - I've never tried the recoil stock kit so I can't compare it to the limb saver pad.
I will, however, echo that ability to handle recoil isn't about the shooter's size. Better ergonomics (shorter LOP) and a reduction in felt recoil certainly help with a smaller shooter's manipulations and tactics. However, better ergonomics must be paired with the right training and then followed by consistent training and drilling to be effective on the shotgun platform.