Depends on if you reload or not. If you reload practically anything and reduce the powder charge. If your buying ammo my thoughts are:
-7mm-08 or 6.5 CR Good choices tend not to have to much recoil.
-270 win I'd do 7mm-08 or 6.5 cr first as they have a little less kick
-308 - Reduced Recoil Load. Nice as it is common and has plenty of different bullet weights.
-243 win. Nothing wrong with it either
Some other things for thoughts:
- Make sure the stock fits, may require aftermarket stock or modifications. (*probably equally important*)
- Limb Saver recoil pads are nice at reducing felt recoil.
- Install a muzzle break, I'm not a massive fan of this, but it does work.
Best wishes, how she enjoys it.