I ordered the 'small world' dress and the bellhop dress in size Large after reading that some may not have much give around the chest. The bellhop dress has elastic panels in the back, very comfy and fit is great. It fit me and my 13 yr old daughter who has a small chest. The fabric is nice and stretchy. I wear a 36C/150lb/5'7 and read that the dresses ran small, along with this and the size chart said the med waist fit 29"- I am not anywhere near this, but all my other dresses are mediums. I was disappointed that the large small world dress was way to big in the chest, the straps are not adjustable and they are way too long. The dress is no longer on the Disney.com, so I may try to shorten the straps and take it in on each side. I don't know for certain that the medium would have fit, but I can pinch quite a bit of fabric on this.