If memory serves, the dresses are in XS (4-5), S (6-7), M (8-10) L (12-14). I don't think they go much bigger than that and the last time we went was 2 years ago so things may have changed since than. Some of the dresses have a fair amount of give to them and you browse the dresses before hand. It is also okay to change the package type in the BBB when you get there if she decides she doesn't want a dress. They can be a little uncomfortable or so I'm told.