I want to get a 12 ga but I can't afford the models that are soft hitting and light enough for her to hold.. She thinks my 10/22 is heavy after a 10rd clip..
The heavier the gun is the less recoil it will exert on the shooter. I would go with a Mossberg 500 or a Remington870 with a nice pad on the buttstock. If she is worried about the weight have her sit on a bench rest. Also places like ammotogo.com have shotgun training rounds. Initially designed for kids they are usually a one inch cartridge that has little to no recoil. Then work your way up :-)
You can't sit on a bench to shoot trap... Like I said before that is the reason for getting her the shotgun.. If I was getting her a rifle then weight wouldn't be a problem...
That's a tough call. But honestly if you can't support the firearm properly then you shouldn't be operating it :-/ if the 10-22 is too heavy and you don't have the money to get the lightweight models like stoger then there really aren't any other options for you :-/