If she is an inexperienced shooter she can be instantly and permanently turned off of shotgunning if she has a bad experience due to recoil. Only you know for sure where she's at as a shooter and how she'll handle the thumping of 100 rounds of 12ga.
IMO if she's a new shooter you should be looking for a gas-operated 20ga autoloader such as a Remington 1100, Beretta 390 or 391, Browning Gold or Silver. The gas operating systems of these shotguns will soak up a ton of recoil and allow her to focus on developing good shooting fundamentals without worrying about getting beat up. If she sticks with it, in time she'll develop good form/technique and will be ready to jump up to a 12ga and enjoy it.
As for patterning...that's a function of the choke that your using as much as anything. 1oz out of a modified choked 12ga and 7/8 oz out of a modified choked 20ga will not make as much difference to a novice as the bad form/technique that develops when you're scared of the recoil.
IMO if she's a new shooter you should be looking for a gas-operated 20ga autoloader such as a Remington 1100, Beretta 390 or 391, Browning Gold or Silver. The gas operating systems of these shotguns will soak up a ton of recoil and allow her to focus on developing good shooting fundamentals without worrying about getting beat up. If she sticks with it, in time she'll develop good form/technique and will be ready to jump up to a 12ga and enjoy it.
As for patterning...that's a function of the choke that your using as much as anything. 1oz out of a modified choked 12ga and 7/8 oz out of a modified choked 20ga will not make as much difference to a novice as the bad form/technique that develops when you're scared of the recoil.
