I agree with you.. I would worry about the scope hitting her. Instead since the shooting will be close, get her a small Wolverine LK-II they have a short barrel and stock so the weight would not be too bad. They are very accurate. In fact you could shoot roundball out of them if you want. Just load 50 grains for starter. Then have her shoot and keep upping the charge. Have her tell you, when the recoil is too much. With open sights there is not the danger of the scope, and since she is shooting short range with young eyes, she should not have any problem working up some kind of a load.

The only reason I worry about getting too light a bullet is then you are loosing the benifit of the rifle. Another good rifle might be a White G Series Whitetail or Bison. They are a solid rifle, recoil is not bad, and they can shoot a conical bullet with deadly accuracy. I shoot 70 grains and a big conical, but I could just as well shoot 70 grains and a sabot projectile. Just another thought for you.