Included in the pattern, which is a design of Lisa Naskrent, are sizes 12 months all the way to size 10:
I ordered the pattern to make one for my Etsy shop in size 18-24 months. The pattern calls for 100% DK cotton yarn, but I decided to use Bernat Baby Sport which worked out just fine.
The pattern was easy to follow and I was able to finish in three (3) evenings. I highly recommend this design for anyone with some crochet experience.
If you would like a "So Hoppy" dress already finished, here is my finished dress that is ready to ship from my Etsy store: