welcome thauch, i bought my wife a 870 youth model in 20 ga., she loves it and will shoot it all day, the disadvantage less shot cap. with the 20,and getting harder to find shells for the 16[&o]the adv. of the 20 ga. a little less recoil, BTW your wife and mine are about the same size and weight, what would this gun be used for (mainly)?

the 20 ga. is a very fun gauge to shoot, every now and then i'll take out the 20 just for fun