I got so frustrated trying to find ##### that fit my 3'9", 60 lb three-year-old that I ended up just buying her size sevens with plans to hem them at home. I'm going to have to take three inches off the bottom just so she doesn't trip. I keep reminding myself that the pediatrician says there's nothing wrong with her. She's shaped like a three year old (chunky thighs, short legs, round belly) but she's scaled up a few sizes, and all the clothes for kids her height are designed for skinny five year olds who have lost their baby fat. The clothes that actually fit in the waist are designed for seven and eight year olds, who apparently have amazingly long legs and dress like miniature prostitutes.
Anyway, I put a hem in her pajama ##### tonight to try it out, and I think it worked OK. I'm trying to figure out how to put in a hem that looks decent but can be easily let down when she has her inevitable growth spurt.
Either that, or she's going to be in dresses and legwarmers all winter, which is what I did last year. It's less practical than it used to be now, though, because of preschool.