I didn't read all the posts, so if I'm repeating just forgive me ... you might want to consider the old .30-30. A Marlin M336 costs a lot less than the bolt guns and it'll kill deer out to around 175-200 yds. It doesn't kick much, ammo is cheap so she can practice a lot, and if you buy a used rifle it'll cost even less. I like that it shoots a slower, heavier bullet than some of the others mentioned (like the .243) and gives great penetration with slow bullet expansion. I like the .243 okay, I just don't like the light bullet weight. The .243 kills like dynamite if you hit one right, but it has a reputation for leaving a lot of wounded critters in the woods if you make a marginal shot.

I've got several rifles ... a .300WSM, a .30-06, and a .308 ... but when it comes time to smoke a buck, my old .30-30 usually does the job just fine if the range is under 200 yds besides,it's just fun to shoot. I shoot 170gr Winchester Power Points, and I've stopped every deer I've ever shot with it right where they stood.

The .243 and some of the other traditional bolt rounds are faster and more glamorous, but for plain ole' deer killing, the .30-30 is hard to beat.