Firme67;
Once upon a time, a fair amount of time ago, Remmie made the 788 in a leftie version. One of the calibers available was 6mm Remington. The 6mm is everything the .243 wants to be when it grows up. The 6 is based on the 7X57 Mauser case rather than the .308 case of the .243. The problem is finding one, they never were a common gun and they're much rarer nowdays.
Therefore, my first choice would be a Tikka lefty in 6.5 Swede. I'd get the hunter, not the lite. The hunter will be a wood stock & therefore easier to shorten to the correct LOP for her. The caliber is a truly excellent all-rounder for most North American game, it will serve the purposes you've outlined extremely well. It's also known for low recoil, outstanding accuracy, and the ability to kill far beyond what it's diameter suggests. The Tikkas are sweet guns that also have an earned reputation for accuracy.
900F