Hi I don't really post here much but I thought I would jump in because I do know a little bit about smocking. Smocking and shirring are very different. Smocking is done by hand, the smocking machine is called a pleater and all it does is pleat the fabric so it can be smocked by hand. Smocking does not have the elasticity as shirring does. I will try to attach a picture of my daughters in their smocked dresses I made for Christmas. The smocked portion as no elasticity at all and is purely for decoration.
PS, Tonya your dresses are very pretty!