"Shot placement" minimum calibre 7 x 57, recommended calibre 30 06 and 7mm Rem Mag.
Here is "the rest of the story":
Tried to get my daughter interested in hunting/shooting when she was younger (10-12); she had no desire at that time. While she was in college, she asked me to teach her how to shoot a handgun, and I willingly obliged. I even bought her a handgun (Charter arms .38 special), and a few weekends ago she asked me about teaching her how to shoot a rifle. I was curious as to why, and the answer somewhat surprised me.......she said she wants to take a zebra. I tried to get her to come along as an observer on my first trip, but she declined, and I think she regrets it. At any rate, I know she is somewhat recoil sensitive, so my intention was to start her out with my air rifle first, then the .22LR, then .22 magnum, and then the next step up in my arsenal is the 6.5x55. I do have a .30-06 and would like her to use that, but that might not be an option.......but then we will see. We have time.....
Yes, I know something "bigger" would be "better"; if it were just me, I'd use my .338 Win. mag and be done with it......but sometimes life ain't so simple.