ORIGINAL: skeeter 7MM
Do you handload? If so have you considered the 7mm 08 for her? My wife is 5' nothing, small framed and hates my 270 win but has no problems with our friends micro hunter in 7mm 08. Though fit certainly has a lot to do with it, the 7mm 08 is a very nice round to shoot for anybody and as a handloader more than capable for upto moose sized game with the proper bullet selected. 140 tsx comes immediately to mind..

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Of course putting a sims or pachmyarpad on will also help emmensely to felt recoil, as long as the pull doesn't change for her. Again fit is of the utmost importance to shootability.
If your not a handloader then I think your original thought of a .308 win is very sound.
Good luck
I was just about to post the same thing. The 7mm-08 is a great cartridge, and a decelerator pad will make all the difference in the world.