You might look at getting a New England Firearms .243, they aren't expensive and they are a single shot, which taught me to make good on the first squeeze everytime. Also it had a heavy bull barrel on it, not too heavy to carry but enought that it made the recoil non-existent, just an idea. I know my brother started with a .223 and while yes it will kill a deer it better be a perfect shot everytime as it will most likely not exit. But from what I hear a .308 has a similar recoil to a .243. But in the end it boils down to what fits her best and what she shoots the best. But every caliber you listed is a solid caliber. The only one that would make myself nervous is the 7mm but if you put a muzzle break on it then I'd say give it a shot too. And as for the Remington 700, I love that rifle, we have two, one in .270 and mine is a .300WM.