I would stick with a 20ga. with a rifled barrel of course. If she is planning on hunting small game, turkey, or skeet shooting then I would opt for a combo shotgun one that comes with two barrels, one being the rifles/cantilever and the other is a field barrel with a few chokes. Mossberg 500, or the Remington 870......Dick's Sporting Goods normally has these two on sale, the Mossberg 500 is roughly $100 less......If wanting a dedicated only slug gun two that come to mind is the single shot H&R and the Savage 220f, I own both I give a slight edge to the Savage. Scopes, there are many stick with a 3-9x40