My 5 year old daughter is very skinny and we get all her bottom half's in either Pumpkin Patch or JK Kids....I tend to stock up on a few items in next size up in the sales. Have found similar problem with shoes too bacause although her feet aren't especially thin, she has tiny skinny ankles.....Future Feet in Ponsonby (not Milford brands as nowhere near as good) are great and they managed to find some shoes to fit her well after about half an hour of trying on different imported brands for something suitable......don't try and go there at peak shopping times though as it is packed with Brits buying clarkes shoes. Rest of the time she lives in crocks as fit doesn't matter as much.