what kind of animals are you planning on hunting? IMO, the 243 is far from an 'excellent' big game cartridge, though it'll do in a pinch. The 7mm08 would be FAR more preferable, especially when loaded with a 120 TTSX or the like - recoil will be very very similar to a 243 with 100+ grainers, but I'd be way more confident with it. Any you also have the option of bigger bullets, in the event that she 'grows into' recoil, and wants to try elk hunting or the like.
Speaking for myself, the 25-06/.260 class is the smallest rifle that I'd want to carry on a hunt - and only then with ultra-premium bullets like the TSX, GMX, a-frame, etc. Just a better margin for error; real-world conditions don't always offer perfect broadside opportunities, and I just wouldn't trust a 243 for a quartering shot. And I almost always have an elk tag on me, too, so whatever I carry, I want to be able to take a shot of opportunity on a larger animal while I'm on my deer hunt.