RE: 308 or 243?
If you know some people that own the different calibers you are interested in why not ask them to let your wife give them a try? Around here most hunters are very happy to see women take an interest in hunting, since they may be all that keeps our sport from becoming extinct.
This way she will not only get to try different calibers but also different rifles as well.
If you have never put a Speer 70 gr simi spitzer thru a deer's vitals from a 223 you have missed out on a serious deer killing machine. A more perfect mushroom would be hard to get from any bullet and yes it'll wreck both lungs.