Thank you so much for the detailed explanations and help. When we did a basic shotgun class a few weeks ago, my daughter was shooting my M4 and a M1 swat team gun. After 75 rounds her shoulder was getting sore, so she switched to a 20ga (not sure which one) and liked it. She said it was easier to shoot. The instructor recomended the 870 youth model for her.
I will heed your advice and take her into a gun store and be fitted with whatever she wants. I am pumped that both my wife and daughter enjoy shooting and learning about guns.
Mark