This item runs at least 2 sizes too small. My daughter is very slender, and we ordered her size based on the sizing measurements. She is 6, and the size we received actually fits my 2.5 year old toddler. No way the sizing is correct!
I ordered this dress in the "intermediate" size many years ago when my oldest daughter was little and it lasted through both her sisters wearing it as well. I just bought it again in a larger size for my youngest. She is 8 years old but extremely petite and slender - she can wear size 6 in some clothing. She had outgrown the Intermediate size a while ago, so I ordered the Medium, or 8-10 and that was too small, as well. I'm sending it back and getting the Large for her because I really do love this dress.