Well, first look at what you already have. Think about changing the stock to a shorter version for fit. Then go drop a few bucks on one of the new high tech recoil pads. They work, and reduce recoil greatly.
The big thing here is not the gun, as almost any shotgun will work to give duckin a try, and if she gets bit, she will soon want to choose her own gun...
The focus should be on making sure her gear is adaquate, warm clothing, good boots, etc.
Her experiance out there is 99% persuit & waiting, 1% pulling the trigger.
A lousy gun with great gear, will be much more enjoyable then a great gun with lousy gear.
If she is warm, dry, comfortable, she will be much more likely to want to go back out that second and third time...... Take her out, play the GUIDE. Put her on the shots, assist every way you can, keep informational conversation going, explain whats happening and why your doing it, complament even on rough moments, and never critasize.
you might just get a new duckin partner......
YES I HUNT LIKE A GIRL!!!! BooYaaaa