Join Date: Jan 2009
Location: Vulcan, Michigan
Judging from what she's already shot and liked I'd say most any non-magnum caliber in the .243/6.5/7mm-08 general class would work out.
When it comes to picking out the gun itself it's far better if she picks that out, not you! If you pick it out and she doesn't like it you won't hear the end of it.
Take her where she can look at and handle several different rifles to see what she likes the looks of and finds comfortable - it may surprise you what she picks.
As an example, when my wife wanted her own shotgun to shoot informal clays and possibly an occasional bird hunt we went to the gunshop and she looked at quite a few - and ended up picking out a Benelli Nova 20 gauge. Now, I know Benelli makes a good gun, but a Nova would have been WAY down on my list if I was picking one out for her (or me). But it just felt "right" to her as soon as she picked it up.