I really saw this one coming... Started by genius jones some 4 years ago, with the already in existence child's Bertoia in stock and the Baby Hairy Bertoia made of closed cell extruded sponge cord, hand knotted to a freshly powdercoated, vintage kid-size Harry Bertoia chair. With that, came the reproduction Barcelona chair which was the cutest (and expensive) thing around.
I guess I wasn't the only one paying attention. Original manufacturers of the licensed pieces, started, little by little, introducing their own versions. Emeco had the Navy 1006 aluminum chair in small size already. Vitra did the Panton for kids, Casalinos started showing at nurseries and Kartell made sure you could have a Louis Ghost mini version too. Then, out of nowhere, came Knoll Studio with the mini versions of Saarinen's Womb chair and Mies' Barcelona.... and also the Mini Bertoia and even Herman Miller made the Rocker version.
Pretty much, you want to play little "decor" with your kid's room and make a little reflection image of what the house is, inside their room. While I think that the mini Panton and Casalino are fun and almost toy like, I think that adding a mini Womb or Barcelona is an overkill. Your kids are going to outgrow those chairs too fast to really enjoy them and later you are going to end with them stored in the attic... not to mention than selling them is going to be a difficult task.
Again, they are fun to watch and the companies do a good job making the small versions but a smart investment... I don't think so.

-joel