I'm with Flave on this one. Get a brake put on the -06 and she'll be good to go. Will reduce felt recoil to something like a .243. Use a 180gr. TSX or similar and she should have good penetration. I would think Phil Shoemaker would probably have some good words of wisdom on this since he's dealt with a huge variety of hunters over the years and his wife and daughter could probably give some advice as well.
If someone needs a muzzle brake to shoot a rifle,it's too much for them. She would be better off with a .270,280,.308,7/08,7x57 loaded with heavy bullets and practice on rabbits. Actually,she would be better off starting with a .243,.257 Rbts,then going up to the .270,.280...etc.
