Learning to shoot left handed is much easier than changing dominant eyes, in my opinion. You can get a left handed or ambidextrous rifle/shotgun for her. I do just fine shooting the right handed rifles I have, since it is just a matter of using another finger for a function, such as flipping off the safety, than was originally intended. Bolt actions look pretty irritating when the hand you would normally use to cycle is all the way on the other side of the weapon. Slide and lever actions are ambidextrous actions. Top mounted cockin handles are easier than side mounted cocking handles, if the handle is on the wrong side. The charging handle of the AR is good for either hand, even if it is in an irritating place. Look for controls that are all on the left side of the receiver, or ones that can be reached with the thumb.