The 7-08 is great, but for what she is doing, I'd consider a Ruger American Compact in 308 with the option of shooting the factory available reduced recoil loads.
There's not much muzzle blast from a 18" 308 with full power loads, and with the Reduced Recoil loads, it will have less recoil than a 30-30 with 4x the range.
In 308, there is insignificant velocity loss in an 18" barrel...plus the barrels they come with generally shoot well.
So while still being light and handy like the Marlin it's a big step up in capability and a good rifle choice.
So would be a Montana, but at 3x the price.
