Re: Recommendations on a rifle for my wife..
If she can shoot a 20ga shotgun, she should be able to handle many calibers...243, 260, 7-08, 308.
Another issue will be how the rifle fits. You need to make sure that the rifle is the right size. A rifle that fits appropriately aids in accuracy and dealing with recoil.
I'm not gonna shoot here. I'm gonna shoot waaaaaaaay over there!