What ever gun you chose for her ,If you can get full size paper deer targets with the vitals on it,It will make a world of diffrence when she squeezes that shot off on a real deer.She will know exactly where to aim at without second thought.And any caliber you chose will bring that deer down on the spot or no more than 30 yrds from where it was standing.Thats if it is within her shooting range and I wouldn't think more than 150 yrds if only got 100yrd target range.